This is the moment crooks smashed open cases to steal jewellery worth up to a billion euros from a German museum once described as 'Fort Knox', after squeezing through a tiny hole to get inside.

The 'small' diamond thieves stole three sets of 'priceless' 18th-century jewellery from Dresden's Green Vault in the early hours of this morning in what could be the world's biggest-ever heist.

Burglars switched off a power supply to the royal palace and broke in through a window before sneaking in through a narrow gap.

Once inside, the brazen raiders smashed open cabinets and stole three jewellery ensembles which were commissioned by Saxony's former ruler Augustus the Strong in an 18th-century show of power.

Hooded thieves were seen on CCTV cameras inside the museum - which is one of the world's oldest - but they escaped in a getaway car before police could arrive and a manhunt has so far proved fruitless.

CCTV showed the gang smashing open cases to steal 'priceless' jewellery worth up to a billion euros from the Gruenes Gewoelbe or Green Vault

One of the gang can be seen in the security footage swinging an axe at the glass cabinet during the raid to get through the reinforced exterior

Two hooded figures were captured on film running into the vault. Police said they targeted smaller items and avoided bulky objects

German Chancellor Angela Merkel standing next to museum director Dirk Syndram during her visit to the Gruenes Gewoelbe (or Green Vault) at the Royal Palace in the eastern German city of Dresden in 2006

The tiny gap the raiders squeezed through can be seen at the bottom left hand corner of the window (pictured) outside the Green Vault in Dresden

A police investigator taking photographs outside the Residenzschloss. Investigators say the thieves squeezed through a small gap in an iron grille over the windows

According to police, two burglars broke part of an iron window grille on the ground floor and smashed the glass behind to get into the adjoining rooms before storming the jewel vault.

Security footage captured the moment the burglars, who were wearing torches on their heads, swung axes at the glass cabinets.

Two black-clothed figures were filmed running into the dark vault and targeting different sections of the secured cases.

One member of the gang could be seen repeatedly striking a vertical cabinet until the reinforced glass shattered and they could gain access to the jewels.

German media described the 'strikingly small thieves' who managed to get through a tiny hole to enter the vault, as leaving behind bulky objects such as vases or paintings.

Liv von Boetticher, correspondent for German broadcaster NTV, described the hole the thieves got through as being 'no bigger than my head'.

She said: 'I am standing near the corner window and I can see that the suspects have made a hole in the bars that is no bigger than my head.

'They must have been really small and really fit. It is no bigger than my head.'

The break-in only lasted only a few minutes, with the emergency call being made at 4.59am and the police arriving at 5.05am - but the raiders had already fled the scene.

The jewels were stolen after thieves set fire to a junction box, cutting power to the museum's alarms, then managed to get through a small gap in a grille of a window on the ground floor

Stolen: A cabinet of 18th-century jewellery (left) which was smashed open and looted by burglars at a German museum today, causing an 'immeasurable' loss

The pieces stolen from the Royal Palace that houses the historic Green Vault including a hairpin Maria Josephas (right) with large diamond by Johann Melchior Dinglinger from 1713 and reworked in 1719 is in the exhibition 'Splendor et laetitia'

A hat clasp of the diamond rose set (left) and a Breast Star of the Polish White Eagle Order (right) that were stolen from the Green Vault early this morning

A chain of 177 Saxon pearls (left) and a hair aigrette in the form of a crescent moon (right) that were both stolen from the Green Vault

Sealed off: A police officer mans a cordon outside the Green Vault museum in Dresden, eastern Germany, this morning following what could be a record art theft

Investigators linked the gang to the an estimated $4.5million (£3.5m) theft of coins from a museum in Berlin in March 2017.

In that heist burglars used a ladder to steal the huge gold coin featuring a bust of Queen Elizabeth II on the front from the Bode Museum.

According to Bild, up to a billion euros' worth of treasures may have been stolen from the Staatliche Kunstsammlungen in Dresden - which would make it the biggest art theft in history.

Experts at the museum, who once boasted that their collection was 'as secure as Fort Knox', said today that the value of the items stolen was 'immeasurable' and pleaded with the thieves not to destroy them.

Tiny thieves carry out 'world's biggest heist' The hooded figures seen in CCTV footage from the raid at the Staatliche Kunstsammlungen in Dresden were described as 'strikingly small'. They were said to have squeezed through a tiny hole in order to get into the Green Vault and smash their way into the cabinets. German media said the bars the raiders got through were 'no bigger than' the size of a human head. The burglars were said to have left behind bulky objects such as vases or paintings and concentrated on smaller items to carry out the 'world's biggest heist'. Investigators linked the gang to another museum burglary in Berlin in 2017. In that heist, thieves broke into the city's Bode Museum through a window at around 3.30am. By the time police arrived the 221lbs coin, known as the Big Maple Leaf, was already gone. The 221lbs coin known as the Big Maple Leaf that was stolen from the Bode Museum A ladder believed to have been used in the raid was found next to nearby railway tracks, but officers found no trace of the thieves. The inch-thick coin, which features a bust of Queen Elizabeth II on the front and maple leaves on the rear, measures more than 20 inches across. Museum owners said the coin is in the Guinness Book of Records because of its purity of 99.99 per cent gold. It has a nominal face value of £800,00, but measured by weight alone the gold contained in the coin would be worth almost £3.5million. Advertisement

Police said they were alerted shortly before 5am by unarmed museum security guards who had spotted two burglars inside the downtown museum on video surveillance cameras.

The building was being patrolled by two guards in the centre of the building, according to German media.

The first officers arrived on the scene within minutes but the thieves had already fled in a waiting getaway car, which managed to elude immediate attempts to find it in the surrounding area and on the nearby highway, Dresden police chief Joerg Kubiessa told reporters.

Police later confirmed that an Audi A6 matching the description of the getaway car was found burned out in an underground parking lot in Dresden.

Investigators suspect that a fire at an electrical junction box near the museum, which took out the streetlights at the time of the robbery, was linked to the crime, police said.

The outage affected lights in front of a window through which the thieves gained entrance, somehow getting through bars and safety glass to reach the Jewel Room.

Police said they have established a special investigation team, codenamed 'Epaulette' and comprising 20 specialist officers, to solve the case.

Investigators have not excluded the possibility more suspects could have been involved.

Museum officials said the sets that were stolen included intricate and dazzling brooches, buttons, buckles and other items decorated with gold, silver, ivory and pearl.

A 'breast bow' with more than 650 diamonds, weighing 600 carats, and a unique sword with a diamond-encrusted handle and scabbard which dates back to 1719 were all taken in the heist.

Other jewels stolen in the raid included a diamond rose hat clasp, a military medal of the Polish White Eagle Order and a chain of 177 Saxon pearls.

The museum also houses include a 25-inch figure of a Moor studded with emeralds and a 648-carat sapphire gifted by Tsar Peter I of Russia at a meeting in 1698.

Other valuable items include a jewel-studded sculpture of an Indian royal court, made out of gold, silver, enamel, precious stones and pearls.

Another is a 1701 golden coffee service by court jeweller Johann Melchior Dinglinger, decorated with lounging cherubs.

Among the baroque collection of more than 4,000 rare objects is the largest blue sapphire in the world, worth around £23million, and a 50-carat cushion-shaped white diamond, worth nearly £10million.

An aigrette for the hair in the form of a sun (left) and a jewel in palmette shape (right) that were stolen from the Green Vault in Dresden this morning

An 'epaulette' of the diamond rose set (left) and a jewel of the Polish White Eagle Order (right) that were stolen from the Green Vault

One of the pieces (above) stolen from the Royal Palace that houses the historic Green Vault (Gruenes Gewoelbe) in Dresden

Police officers working behind a taped off area at the Schinkelwache building today following the brazen heist at Dresden's Green Vault

Investigation: A police officer wearing gloves and a mask works at the crime scene outside Dresden's royal palace this morning following the break-in

Means of entry? A window at the side of the building where the thieves - who were said to be noticeably small - are feared to have forced their way inside

Marion Ackermann (right), director general of the Staatliche Kunstsammlungen Dresden, and Dirk Syndram (left), director of the Green Vault and the Armory of the Staatliche Kunstsammlungen Dresden today

What are the world's biggest heists? Up to one billion euros' (£850million or $1.1billion) worth of treasures may have been stolen in today's break-in which would make it the largest heist ever. It would surpass a series of other famous thefts, including: Theft of the Mona Lisa, Paris- $700million at today's prices Leonardo da Vinci's masterpiece was stolen from the Louvre in Paris in 1911. The thief, Vincenzo Peruggia, eventually took it to Italy, where it was recovered and returned in 1914. When it was assessed for insurance in the 1960s, the Mona Lisa was valued at $100million - meaning it would be worth around $700million today. Gardner Museum, Boston - $500million In March 1990, two thieves stole 13 artworks worth $500million from the Isabella Stewart Gardner Museum in Boston, Massachusetts. The pair disguised themselves as Boston police officers and left with works of art by Rembrandt and Manet among others. The crime remains unsolved and last year the museum renewed an offer of $10million to help find the artworks. Hatton Garden, London - estimates up to £200million A gang of ageing criminals ransacked 73 deposit boxes at the Hatton Garden Safety Deposit building in London's jewellery district in 2015. Disguised as workmen, they abseiled down a lift shaft over the Easter weekend and used a diamond-tipped drill to cut through the vault wall. The thieves stole gold, silver, diamonds and jewellery and some estimates at the time put the value at up to £200million. Nazi theft of Adele Bloch-Bauer I - $135million A painting of his wife by Jewish artist Ferdinand Bloch-Bauer was stolen by the Nazis in 1941. It remained in Austria until 2006 when it was returned to the Bloch-Bauer family and sold for what was then a record $135million. The Scream, Oslo - $120million Edvard Munch's iconic painting The Scream was stolen by armed robbers in broad daylight in 2004. It was recovered by police two years later and one of the thieves died while still at large. In 2012, another version of the painting was sold in the US for $120million. Diamond heist, Antwerp - $100million In 2003, thieves cleared vaults at the Antwerp Diamond Centre during a weekend, with diamonds, gold and jewellery worth over $100million taken. The thieves got past infrared heat detectors and a lock with millions of possible combinations. Advertisement

At a press conference this afternoon, museum director Marion Ackermann said she was 'shocked' by the 'brutality' of the 5am raid.

Thieves smashed into a glass cabinet and made off with three sets of jewellery which were made for Augustus the Strong, the elector of Saxony in the 18th century, she explained.

Augustus competed with French monarch Louis XIV to assemble the most extravagant jewellery, she explained, describing the items stolen as 'state treasures of the 18th century'.

Augustus, who was elector of Saxony from 1694 to 1733 and also king of Poland for much of that time, established Dresden as a cultural centre and founded the museum which was targeted today.

The material worth of the jewellery was less important than the fact that the jewels had come as a set, Ackermann said.

Asked about the suggested value of a billion euros (£850million), she said the value of the items stolen could not be quantified.

'We're dealing with priceless artistic and cultural treasures,' she told reporters in Dresden this afternoon. 'We cannot give a value because it is impossible to sell.'

Pleading with the thieves not to destroy the objects or melt them down, she said the jewellery was of 'inestimable cultural and historical value' and could never be sold on the open market.

Dirk Syndram, another director at the museum, said the sets amounted to 'a kind of world heritage', totalling about 100 jewellery items.

He explained that the stolen sets were part of a ten-set collection which includes not only diamonds, but also sapphires, rubies and emeralds.

He said: 'Nowhere in any other collection in Europe have jewels or sets of jewels been preserved in this form and quantity. The value is really in the ensemble.'

One expert has already warned that it will be difficult to trace the diamonds if they are not found in the next few days.

The thieves may well break them up and sell them in separate parts as trying to sell a whole ensemble would look too suspicious, said Tobias Kormind of jewellery firm 77Diamonds.

Police say they were alerted to the break-in at 4.59am and suspect that the thieves were behind an electrical fire which broke out nearby.

Shutting off the electricity may have helped the burglars to disable the museum's alarm systems and also left the area in darkness. It is unclear whether the alarms had a backup power supply.

In addition, a burned-out vehicle was discovered nearby and detectives are now trying to track down the owner to establish whether the fire was related to the theft.

Reports in Germany say the thieves were 'noticeably small' and able to fit through a tiny space in a window.

Dresden police said they were in contact with colleagues in Berlin to examine 'if there are any connections and if there are similar patterns in the crimes'.

Germany's culture minister Monika Gruetters said that protection of museums and cultural institutions was now of 'the highest priority'.

'The theft of items which make up our identity as a nation of culture strikes at our hearts,' she said.

It was described as the 'largest art theft in post-war history', according to the German media.

Taken: An image of the stolen goods in their cabinet is displayed at a press conference on Monday afternoon in Dresden

A map showing where the break-in took place this morning and the bridge where the thieves are believed to have cut off a power supply to help them gain entry

Forensic investigation: A specialist police officer arrives near Dresden's former royal palace to investigate the theft today

Inquiry: Police officers work behind a cordon tape at the museum, which was closed to visitors today after the early-morning break-in

Police tape hangs across a doorway at the Dresden museum, where thieves broke in after the power supply was stopped and a fire broke out

Doors closed: A sign at the entrance of the Green Vault informs visitors that no tickets are available today following the break-in on Monday morning

Search for evidence: A police officer scours the steps of the Dresden royal palace for evidence on Monday morning following a 5am raid on the museum

Search: A German policeman looks for evidence outside the Dresden royal palace which houses the Green Vault where thieves staged a break-in this morning

Crime scene: A police van parks outside the historic museum today following a break-in

A view of Dresden's former royal palace today where the collection of treasures is on display

Targeted: Visitors at the Green Vault in Dresden where thieves are feared to have stolen up to a billion euros' worth of treasure in an early-morning heist today

Stolen diamonds 'may be broken up and sold' The diamond sets stolen in Dresden today may be broken up and sold, because trying to sell the whole ensembles would be too suspicious, an expert has said. Tobias Kormind, managing director of jewellery firm 77Diamonds, said the chances of recovering the goods will fall 'dramatically' if they are not found in the next few days. Therefore, they are likely to recut the diamonds individually to make them untraceable, he suggested. Alternatively, the thieves may hope to persuade an 'oligarch' to keep the stolen items in a vault, he said. 'Since the pieces are set within famous statues and art works, it will be impossible to sell them - they are too easy to identify as stolen,' he said. 'Most likely the thieves will break up the works and remove the stones and recut them individually, which destroys a lot of the value. 'The white diamonds can easily be recut and become untraceable. 'If the thieves are smart and are not caught in the next few days, the chances decrease dramatically that the goods can ever be recovered. 'But the thieves need to cover their tracks very carefully. If even one stone is traced, then the chain may quickly link back and some portion of the goods will be recovered.' Advertisement

A €1billion art theft would be comfortably the largest in history, surpassing the $500million raid on the Gardner Museum in Boston nearly 30 years ago.

Two thieves disguised as police officers stole 13 works of art from the Boston museum in March 1990 and the crime remains unsolved.

In 1911 a thief stole the Mona Lisa from the Louvre in Paris. According to an estimate in the 1960s, the painting could be worth around $700million today.

At the press conference on Monday, police said that the smashed cabinet had been made of special safety glass but that it was unclear how the thieves had broken it.

Detectives are now examining the video footage on which two people are seen, but others may have been waiting outside to help them escape in a getaway car.

A getaway car could have been well on its way to the motorway within minutes of leaving the museum, they warned.

State police officers have been at the crime scene investigating how the thieves got inside and stole the jewellery.

'We have not identified a perpetrator and nor have we yet made any arrests,' police spokesman Marko Laske said.

A notice on the museum's website this morning states only that the building is closed today for 'organisational reasons'. It is not expected to re-open before Wednesday.

'Not only our state collections but we the people of Saxony have been robbed,' said regional premier Michael Kretschmer.

'You cannot understand the history of our state without the Green Vault. The treasures found there were made by the hard work of people in our state.'

The security measures at the museum had appeared to be in order and 'comprehensive', he said.

State interior minister Roland Woeller said it was a 'bitter day for the cultural heritage of Saxony'.

The thieves 'stole cultural treasures of immeasurable worth - that is not only the material worth but also the intangible worth to the state of Saxony, which is impossible to estimate,' he said.

Targeted: Visitors at the Green Vault in Dresden where thieves are feared to have stolen up to a billion euros' worth of treasure in an early-morning heist today

A police van parks outside the Green Vault museum in Dresden today following a burglary of items feared to be worth up to a billion euros (£850million)

Presence: A police officer walks through the gates of the city palace today in Dresden where authorities are investigating a massive art theft

Dresden's former royal palace - the home of the former electors and kings of Saxony in the centuries before Germany was unified - is seen today

Dresden's Green Vault takes its name from the green-coloured columns and decoration in rooms such as this one

VIP visitors: German chancellor Angela Merkel hosted then-US president Barack Obama at the Green Vault in Dresden in 2009 (pictured)

The Dresden museum was founded by in 1723 and houses thousands of items including historic coins and jewellery.

However, one of its most valuable treasures - a 41-carat naturally green diamond called the Dresden Green - is currently out on loan in New York.

The museum did not put a current value on the piece, but said that at the time of its purchase it cost 400,000 thalers, compared to the 288,000 thalers it cost to build the city's lavish Frauenkirche church at around the same time.

In 2010, then-museum director Martin Roth boasted in an interview with Die Welt that the Green Vault was 'as secure as Fort Knox'.

Roth explained how the vault was protected by 'invisible' security systems, but warned that the biggest danger was information leaking out from inside.

The collection dates back to 1723, while the Dresden royal palace which houses it was first built in 1533 as the home for the electors and later kings of Saxony.

The Green Vault gets its name from the green-coloured columns and decoration in some of the rooms.

A police officer kneels down by the steps of the royal palace today as he investigates the break-in at Dresden's Green Vault

Pictured left: Police officers outside the entrance to the Green Vault this morning; right: an investigator works at the scene of a cordon

Treasures: Visitors look at the collection in Dresden's Green Vault which dates back to the 18th century and contains thousands of items

Precious: Some of the gemstones in the museum's collection are seen in this file picture

The museum and palace were rebuilt after the devastating Allied bombing of Dresden in World War II. Some of the items were looted by Soviet troops in 1945, but later returned.

Part of the collection remained closed to visitors during the Cold War, when Dresden was part of communist East Germany.

However, the museum was extensively rebuilt in the 2000s and its two exhibitions now form one of the 'best-preserved treasuries in Europe', its website says.

Angela Merkel hosted then-US President Barack Obama there in 2009 during his early months in office.

In 2017, a 220lb gold coin the size of a manhole cover was stolen from a Berlin museum and is feared to have been melted down.

Prosecutors allege that the burglars broke into the museum through an upstairs window and used a ladder, wheelbarrow and rope to extract the coin. A trial remains underway.