Heavy-duty: The drill that was used by thieves during the brazen £60million Hatton Garden heist

This is the drill that was used by thieves during the £60million Hatton Garden heist over the Easter weekend.

The gang used the power tool to cut through the wall of the secured vault where they raided 72 security boxes before escaping with wheelie bins full of precious gems.

The photograph of the Hilti DD350 drill was released tonight by Scotland Yard as the officer in charge of the investigation said the crime had been carried out by an 'Ocean's 11 type team'.

Police are offering a £20,000 reward for information leading to the arrest and conviction of those involved in the raid.

The six men were captured on CCTV as they carried out the bold raid in London's diamond district.

They used the drill to cut through a concrete wall into the bank's strongroom, where they ransacked security vaults.

But, amazingly, the hole used by the gang was just 45cm wide and 25cm high - meaning they would have had something of a squeeze to muscle their way into the basement.

Images of the scene show the mayhem that detectives discovered when they arrived at the crime scene in London's diamond district.

Safety deposit boxes were strewn across the floor while power tools - including the heavy duty Hilti DD350 used to access the vaults - were discarded nearby.

Scotland Yard also described how there was rubbish covering the Hatton Garden basement, while the wrought-iron cage door had been broken down. An angle grinder, concrete drills and crowbars were found amid the security boxes.

Officers said there was no sign of forced entry to the outside of the building, indicating that they had a key or that someone had let them in from the inside.

One of the theories behind the heist is that a member of the gang had rented a space within the premises.

The Hatton Garden Safe Deposit Company is housed in a seven-storey building, which accommodates 60 other businesses, including watch traders and diamond wholesalers.

The thieves appeared to have disabled the communal lift on the second floor, before using the lift shaft - which was destroyed when police officers arrived at the scene - to climb down to the vault.

Breaking in: The gang used the power tool to cut through the concrete wall of the secured vault, pictured

Caught on CCTV: Scotland Yard previously released several images of the gang as they entered the premises

Reward: Police are offering a £20k reward for information leading to the arrest and conviction of the criminal

Unaware: The men had their faces covered, but sources have suggested they were not aware of the camera

They then opened shutter doors into the basement, before boring holes into the basement wall.

Appearing on the BBC's Crimewatch tonight, Detective Superintendent Craig Turner, head of the Flying Squad, said that the theft had been carried out by an 'almost Ocean's 11 type team'.

Mr Turner said: 'This was a particularly ambitious burglary to say the least and has affected so many victims.

'People's property has been taken, people's pensions, people's heirlooms which obviously can't be replaced by insurance firms.

'We may well be misled - this is carried out by an almost Ocean's 11 type team, but in essence there are victims behind this and these are callous thieves.'

Destruction: Dramatic pictures released yesterday show the scenes of chaos found by detectives when they arrived at the crime scene in London, where burglars had strewn safety deposit boxes across the floor

Covered in dust and debris: Left, the forced door to the vault and, right, the mess left in the corridor

Inside knowledge: The gang managed to access the security boxes without damaging the vault door, pictured

Carefully planned: Officers said there was no sign of forced entry to the building and that the thieves had disabled the communal lift on the second floor and then used the lift shaft (pictured) to climb down

Peter Kirkham, a former DCI with the Met Police who worked for the Flying Squad for five years in the mid-90s, said police photos of the scene supported his belief that the heist was an inside job.

Another former Flying Squad detective said: 'Everything you see indicates a very specialist knowledge both in what was inside the building and how to deal with it.

WHEN DID THE HEIST HAPPEN? Thursday, April 2: Workers from businesses in the building go home for long Easter weekend. Some have claimed the thieves were already hiding inside the building waiting to be locked in. Friday, April 3: Police have found no signs of forced entry at the premises, but an intruder alarm sounded at the safety deposit business in the basement at 00:21. No police car was sent. Traders have claimed a security guard attended the site but said he 'wasn't paid enough' to look inside the vaults. Saturday, April 4, Sunday April 5 and Monday, April 6: The exact time of the raid has not been confirmed, but given the amount of time it would have taken to drill through the concrete wall and opened 70 safety deposit boxes, it is thought to have taken many hours. Tuesday, April 7: At 8am, workers return to the building and finding 'scenes of chaos'. They call the police, who attend. Advertisement

'There is an expertise, combined with strength, patience, determination and, probably, an inside knowledge.'

Releasing the scene images yesterday, Scotland Yard said forensics had finished examining the scene and that it had taken a 'significant amount of time'.

The force said the team had recorded, packaged and recovered approximately 400 exhibits, including items for DNA profiling, fingerprints and other evidence.

Specialist forensic photographers have also mapped out the crime scene and utilised digital techniques to record the inside of the premises, it said.

Speaking tonight, Mr Turner appealed for members of the public who may have been in the Hatton Garden area during the theft and who may have seen anything suspicious to come forward.

Describing the drill that had been found at the scene as a 'specialised bit of equipment', he called for members of the criminal community who may have seen the gang in possession of it to get in touch.

There are still six victims who have not been identified yet by police, Mr Turner said.

'I appeal to any of those victims who haven't been contacted by police to contact the incident room,' he added.

The police previously released CCTV footage showing the suspects believed to be involved in the heist