A LORRY driver passed out when he opened the door to check some paperwork and discovered the bodies of 39 Chinese migrants, it has been reported.

Dad-to-be Maurice 'Mo' Robinson, 25, is still being quizzed on suspicion of murder after he picked the trailer packed with bodies up from Purfleet in Essex yesterday.

24 Essex lorry deaths - Mo Robinson has been arrested on suspicion of murder after 39 bodies were found in a lorry in Essex

24 Essex lorry deaths - Police are today searching around the industrial park where the lorry was found Credit: Paul Edwards - The Sun

24 Essex lorry deaths - A huge group of Chinese migrants were found dead discovered in Grays, Essex Credit: Splash News

The grisly discovery is one of Britain's biggest-ever mass murder probes after the bodies were found on an industrial estate in Grays yesterday morning.

Robinson passed out when he opened the doors to fetch some paperwork and discovered the bodies, a horrified witness told the Evening Standard.

The witness' claims have not been confirmed by Essex Police, who have been granted an extra 24 hours to question Robinson after he was arrested at 1.40am yesterday.

One pal told Mail Online: "When he opened the container up and saw all the dead bodies, he was absolutely horrified - as anyone would be - and called the ambulance service who in turn alerted the police.

"I heard the container was refrigerated - the temperature was -25 degrees and the bodies were frozen and had been dead for some time."

WHAT WE KNOW SO FAR:

39 adults found dead on truck in Grays, Essex, believed to have frozen to death

Police confirm the victims are Chinese nationals including eight women

Lorry trailer registered in Varna, Bulgaria, and travelled into Purfleet, Essex, from Zeebrugge, in Belgium

Driver Maurice 'Mo' Robinson, 25, from Northern Ireland arrested on suspicion of murder

National Crime Agency investigating possible people smuggling gang

Police raid three houses in Co Armagh, N. Ireland

Essex Police have reported all the 39 victims - including a teenager - are from China. They said eight of the victims were women and the remaining 31 men.

Cops have described one of the women as a "young adult" but no other indication of the age of the victims has been released.

Bodies are now being moved by private ambulance with a police escort from Tilbury Docks to Broomfield Hospital so post-mortem examinations can be carried out.

The horror has chilling echoes of 2000, when 58 Chinese stowaways died in a lorry travelling by ferry from Belgium to Britain.

In both tragedies, the victims had come from Zeebrugge in to Purfleet port in Essex.

Mo Robinson, who brands the lorry "The Polar Express" on social media, had picked up the trailer after it arrived from Zeebrugge, Belgium at 12.30am yesterday.

Cops investigating the deaths last night swooped on three homes in County Armagh, which are related to Essex Police's murder probe into Robinson.

Among the houses being searched are Robinson's home near Markethill and his parent's home in Laurelvale.

24 Police last night raided two homes in County Armagh - including Mo Robinson's parent's home in Laurelvale Credit: Pacemaker Press

24 Mo Robinson's parents are understood to have travelled to England Credit: Pacemaker Press

24 They also searched Mo Robinson's home in connection with his arrest Credit: Pacemaker Press

24 Police have been given an extra 24 hours to question Mo Robinson Credit: Pacemaker Press

24 The inside of the lorry where the 39 bodies were found in Essex Credit: EDDIE MITCHELL

24 Police yesterday evening drove away the lorry that the 39 dead bodies were found in Credit: EPA

24 Cops were seen bowing their heads as the truck drove past Credit: AFP or licensors

24 CCTV shows the final journey of the lorry carrying 39 suspected migrants

Robinson, who has been a HGV driver for more than five years, doesn't own the lorry.

The lorry was registered in Varna, Bulgaria, in 2017 by an Irish company but has not returned to Bulgaria since then.

Varna is notorious for cigarette and fuel smuggling and has known links to Irish Republican gangs.

Detectives from the National Crime Agency are now investigating whether an Irish people smuggling gang with links to Bulgaria was behind the horror.

Global Trailer Rentals Ltd (GTR) have confirmed to RTE News they own the container and that they leased it on October 15 from their yard in Co Monaghan for £238.22 a week.

A spokesperson said they had contacted Essex Police to give them information about the person and company that leased the trailer.

GTR, who will also hand over data from its tracking system, added they were "shellshocked" and "gutted".

Last night sources close to Irish police said the lorry’s refrigeration unit - which could have plunged temperatures as low as -25C - was turned on, leaving those inside with "no chance of survival".

Do you know Mo Robinson? Call The Sun Online on 0207 782 4368 or email tips@news.co.uk

Even if the trailer was not chilled the victims may have suffered agonising deaths as oxygen slowly ran out.

Richard Burnett, CEO of the Road Haulage Association, told The Sun: “If it’s chilled, the trailer temperature will be set to -5C, but if it’s frozen you’re talking about -25C.

“There’s little or no chance of survival if you’re in those conditions for any length of time.”

CCTV shows the lorry making its final journey packed with the dead suspected migrants - including one teenager - 30 minutes before the grim discovery was made.

DRIVER ARRESTED

Robinson's social media is awash with pictures of what appears to be the same cab as the lorry involved in the horror - including an identical “The Ultimate Dream” decal on the windscreen.

The driver has also used the hashtag "irishfridgemen" and "cowboy club" while posting about the lorry on Instagram.

His family, from County Armagh, told Belfast Telegraph they hadn’t “heard from him” and “don’t know what is going on”.

They are said to be flying from Northern Ireland to England to offer their support.

BELGIUM TO BRITAIN

Police say the lorry's cab travelled from Holyhead on Saturday, while the trailer - with the 39 bodies - travelled 173 miles from Zeebrugge in Belgium to Purfleet, Essex.

It was then unloaded from the ferry in Purfleet at 12.30am, and attached to Robinson's lorry.

Both lorry and trailer then left the port at 1.05am. Less than 35 minutes later ambulance and police made the grim discovery of the 39 bodies in the back.

Cops warned the government three years ago that people smugglers were targeting Purfleet as it was "less busy" than other ports.

The Federal Public Prosecutor’s office in Belgium believe the container arrived in Zeebrugge on October 22 at 2.49pm.

'YOU'RE GOING TO DIE'

Mayor of Zeebrugge Dirk De Fauw told local press he believes the migrants must already have been dead before they reached the port.

He called the ferry terminal "extremely well-guarded" and explained the container was sealed with no heat allowed in.

De Fauw added: "If you end up in such a box with 39 people, you're going to die."

Around 4,000 containers are shipped across the Channel from Belgium to the UK every day - with checks using Co2 detectors only made on those with a canvas top.

Those that are refrigerated won't be checked if there is no sign the seal has been tampered with.

Sources close to Irish police said the container was normally used to transport biscuits.

The lorry had been captured on Automatic Number Plate Recognition 25 times in recent weeks between Dublin and Holyhead.

24 The lorry driver remained in police custody yesterday evening

24 Robinson has posted about the truck, which he calls The Polar Express, on Facebook

24 Robinson joking about with a police officer Credit: Rex Features

24 He previously posted this picture of him posing with a cowboy hat next to a truck

24 The container is believed to have been transported from Zeebrugge to the UK on the Clementine ferry

24 Suspected migrants are detained in Zeebrugge today Credit: PA:Press Association

24 Police at the industrial estate in Grays today Credit: Paul Edwards - The Sun

24 Police officer's sign a book of condolence paying tribute to the victims Credit: PA:Press Association

'THEY SHOULD BE HUNTED DOWN'

Police are now working to the identify the 38 adults and one teenager but say it will be a "lengthy process".

They were alerted by paramedics but it is not clear who made the original discovery. All 39 people were dead before the emergency services arrived.

Boris Johnson said during PMQs that the perpetrators "should be hunted down and brought to justice".

The National Crime Agency confirmed they are assisting Essex Police and Immigration Enforcement to "urgently identify any organised crime groups" who may be involved.

Britain's biggest murder probes In 2000 58 dead bodies were found in a lorry at Dover, after travelling from Belgium. The driver was sentenced to 14 years in jail for his part in a people smuggling operation.

British doctor Harold Shipman was found guilty of murdering 15 people in 2000. An inquiry found 218 victims, 80 per cent of whom were elderly women.

Bruce George Peter Lee is one of Britain's most prolific killers. He was convicted of 26 counts of manslaughter (11 were later overturned) in 1981.

Dennis Nilsen was jailed for life in 1983 after murdering 15 men. He picked his victims up from the streets and strangled or drowned them before having sex with their corpses.

Peter Sutcliffe, the "Yorkshire Ripper" murdered 13 women and attempted to kill seven others. He carried out his despicable crimes between 1975 and 1980.

Argus Sinclair spent much of his life behind bars for a catalogue of crimes - he was convicted of killing four people, but suspected of murdering more.

Beverley Allitt was sentenced to life in prison in 1991 after killing four babies and wounding nine others while working as a paediatric nurse.

Ian Brady murdered five children, aged between 10 and 17, and buried them in Saddleworth Moor.

In 2000, 58 Chinese stowaways died in a lorry travelling by ferry from Belgium to Britain.

They were immigrants and likely died of asphyxiation after being trapped in the container for more than 18 hours.

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The driver, Perry Wacker, was sentenced to 14 years in jail for his part in a people smuggling operation run by a Chinese gang.

And in 2004, 23 Chinese cockle pickers who were searching for a "better life" drowned in Morecambe Bay, Lancs, when they were trapped by sweeping tides.

Anyone concerned about relatives following the incident can call a Casualty Bureau on 0800 056 0944 or 0207 158 0010 if ringing from outside the UK.

24 A forensic tent at the scene in Grays today Credit: PA:Press Association

24 Forensic officers comb for clues today Credit: Getty Images - Getty

24 Cops have called it an 'absolute tragedy' Credit: Paul Edwards - The Sun

24 The lorry has a decal reading 'The Ultimate Dream' Credit: PA:Press Association

24 Police have not released any further information Credit: PA:Press Association