A police officer has described the moment he discovered the half-naked bodies of 39 migrants, some of whom were 'frothing at the mouth', in the back of a lorry.
It comes as the jury were shown CCTV footage which dramatically captured the moment steam billowed out of the trailer after lorry driver Maurice Robinson opened the doors to give them air only to discover they had died.
As Robinson was 'arrested at the scene, another officer radioed control reporting that there were 'potentially 40 people deceased'.
Pc Jack Emerson was among the first to arrive at the lorry in Grays, Essex after driver Maurice Robinson dialled 999 early on October 23 last year.
Robinson, 26, had picked up the trailer from Purfleet docks after it was transported from Zeebrugge in Belgium, the Old Bailey has heard.
He opened the doors to the trailer minutes after leaving Purfleet but drove around and spoke to haulage boss Ronan Hughes and alleged organiser Gheorghe Nica by phone before alerting emergency services, jurors were told.
When police arrived on the scene at 1.50am, Robinson was 'just standing there' and appeared calm, according to Pc Emerson.
The court was shown CCTV of marked police cars arriving in Eastern Avenue, Thurrock, where Robinson's lorry was parked with the rear trailer door open.
Video showing officers arriving at the scene, where Maurice Robinson (top right) had found the bodies of 39 Vietnamese migrants in a lorry container after he was told to 'give them air'
Describing the scene, Pc Emerson said: 'I could see one of the trailer doors was already open and I could visibly see numerous half-naked bodies in the back of the trailer, lying on the trailer floor motionless.
'I approached the door of the trailer to further inspect the bodies and it became apparent as I got closer that the entire trailer was full of bodies, and the individuals appeared to be half-naked.
'Most of them were wearing clothes on their lower half but they all appeared to not be wearing any clothing on their upper half.
'All of the bodies appeared intact and it was in my opinion that they had not been there for a very long period of time as there was not any visible sign of decomposure.
'There was however a strange smell coming from the trailer that smelt like chemicals.
PC Cohen and PC Wyn arrived on the scene after PC Jack Emerson who responded to the 999 call from Maurice Robinson (top right) reporting the fact the migrants were not breathing
Video played to the court showed the moment officers arrived on scene in Essex and (inset) body cam footage shows an officer looking for signs of life inside the lorry after arriving
'There was also smoke condensation coming from the rear of the trailer which suggested to me that the trailer was refrigerated.'
The officer said in a statement read to the court that the driver was arrested on suspicion of murder after a colleague called to 'get him in cuffs'.
Another officer radioed control saying there was 'potentially 40 people deceased'.
Court told Kennedy sent series of texts to friend about incident
Christopher Kennedy, 24, who is on trial accused of conspiracy to assist unlawful immigration, exchanged a series of texts with a contact about the incident hours after the bodies were discovered, the court heard.
The friend asked: 'Who's is the BG yoke got in Essex with the bodies?'
Kennedy named Ronan Hughes, adding: 'Some mess.'
Asked what happened, he replied: 'Dunno must have been 2 meany and run out of air (sic).'
The friend wrote: 'End of the road for him and drive.'
Kennedy added: 'He never see day light again.'
Pc Emerson said he got inside the trailer to search for any signs of life, checking pulses and for breathing.
He said the bodies were 'closely packed' together, mainly lying on their backs.
'I immediately started scanning the trailer to look for signs of life but there was not. All bodies appeared completely motionless.
'Due to how packed together the bodies were in the trailer it was not possible to check every body so I made an attempt to check the bodies I could reach.'
He said some of them appeared to be 'frothing from the mouth' and some were warm.
Jurors heard that the Vietnamese nationals, aged 15 to 44, were pronounced dead at 2.40am on October 23 last year.
It comes after jurors were played horrifying footage showing steam rising from the container where the Vietnamese migrants had suffocated to death at temperatures above 100 degrees.
Trucker Maurice Robinson can be seen approaching the rear right hand door of his lorry and opening it.
As he slowly eases the door open steam from the bodies of the deceased gushes out and he steps back.
Robinson had pulled up at Eastern Avenue, Grays, Essex, at 1.13am on 23 October having picked the lorry up from Purfleet.
It was only after 23 minutes that Robinson phoned the police in a panic.
Prosecutor Bill Emlyn Jones said Robinson made two calls to haulier Ronan Hughes who had earlier instructed him to 'give them air quickly. Don't let them out'.
Robinson dialled 999 at 1.36am.
Lorry driver Maurice Robinson (pictured), 26, has already admitted 39 counts of manslaughter
CCTV image issued by Essex Police of snapchat message from Ronan Hughes to Maurice Robinson, which was shown at the Old Bailey, London, shortly before he discovered bodies
The court was played an emergency call Robinson made in which he said: 'They are all lying on the ground.'
The operator asked: 'Are they breathing?'
Robinson: 'No, I don't think so. I heard a noise in the back, so I opened the door.'
Operator: 'How many patients?'
Robinson: 'About 25.'
Operator: 'And they're not breathing?'
Jurors were shown a screen grab from the phone of Robinson, who had collected the trailer from Purfleet port.
CCTV footage played to the jury showed large amounts of steam escaping from the back of the trailer when Robinson opened the doors shortly before he called the emergency services
Who is charged with what in the lorry case?
Eamonn Harrison, 23Denies 39 counts of manslaughterDenies conspiracy to assist unlawful immigration
Gheorghe Nica, 43Denies 39 counts of manslaughterAdmits conspiracy to assist unlawful immigration
Valentin Calota, 37Denies conspiracy to assist unlawful immigration
Christopher Kennedy, 24Denies conspiracy to assist unlawful immigration
Maurice Robinson, 26Admits 39 counts of manslaughterAdmits conspiracy to assist unlawful immigration
Ronan Hughes, 41Admits 39 counts of manslaughter Admits conspiracy to assist unlawful immigration
The prosecutor said it was a photograph of a text exchange he had on Snapchat with someone with the user name RHughes301.
It read: 'Give them air quickly. Don't let them out.' Robinson replied with a thumbs-up emoji, said the prosecutor.
Jurors were told the exchange happened sometime between midnight and 1.20am.
The Old Bailey has heard dying victims wrote desperate text messages to their families as the air ran out and the temperature rose to 101.3F.
Jurors were told the ferry MV Clementine left the Belgian port at 4pm UK time for a journey that lasted more than eight hours.
At 6.25pm, a young Vietnamese woman took a series of selfies on her phone showing the sweltering conditions inside.
Over the next couple of hours, occupants attempted to make phone calls, with one calling the emergency number for Vietnamese police, without success.
In a recorded message to his family, Nguyen Tho Tuan, 25, said: 'I'm sorry. I cannot take care of you. I'm sorry. I'm sorry. I cannot breathe.
'I want to come back to my family. Have a good life.'
In another mobile phone recording at 8.02pm, Nguyen Dinh Luong, 20, said: 'I cannot breathe. I'm sorry, I have to go now.'
In the background, a voice could be heard saying: 'Come on everyone. Open up, open up.'
In another phone recording two minutes later, the same victim said: 'I'm sorry. It's all my fault.'
A voice in the background then says: 'He's dead.'
Nguyen Huy Hung (left), 15, was the youngest, while Nguyen Dinh Lurong (right), 20, also died
Earlier, the court was told the tragic migrants would have been cut off from the world as soon as the trailer doors were closed.
Some of them repeatedly attempted to make phone calls, with one dialling the emergency number for Vietnamese police, without success as they struggled to breathe during their journey from Zeebrugge, jurors have heard.
Julian Skeith, who analysed cell site data, told jurors that he found the victims' mobiles could not connect to the network when the trailer doors were shut.
Prosecutor Jonathan Polnay said: 'We know one of the handsets in the trailer belonging to one of the deceased was able to connect to the network in Belgium because we have data from the network company.'
Asked to account for that, Mr Skeith said: 'I would not say it's impossible to make a call from the rear of the trailer.
'All I can report to you, when I carried out my survey, I could not.'
Anna Bui Thi Nhung, 19, (left) and cousins Nguyen van Hung, 33, (centre) and Hoang Van Tiep (right), 18, were also among those who died in the horrific incident in October 2019
Pham Tra My (left and right) 26, was among the 39 people who died in the lorry in Grays, Essex
The witness also looked at mobile phones attributed to members of the alleged people-smuggling ring.
The prosecution has alleged there were two successful people-smuggling runs on October 11 and 18 last year, before the trip that ended in tragedy on October 23.
Cell site data suggested some of the alleged plotters were in the area of Orsett, Essex, at the time migrants were allegedly transferred from trailers for onward transportation to south-east London on the earlier occasions.
Nica's phone was placed at the same location around the time Robinson discovered the migrants had died, the court heard.
Cargo operator Jason Rook said in a statement that he smelt a 'decomposing smell' as he unloaded the trailer.
The prosecutor said the temperature inside the trailer reached a maximum of 101.3F sometime after 9pm.
Jurors heard that between 10pm and 10.30pm the carbon dioxide (CO2) inside the trailer had reached its toxic threshold, though the prosecutor said that was not agreed evidence and the jury would hear from witnesses.
Eamonn Harrison, 23, from Mayobridge, County Down, allegedly drove the trailer to the Zeebrugge ferry port.
He denies 39 manslaughter charges and conspiracy to assist unlawful immigration.
In October last year, men, women and children, aged 15 to 44, were found dead in the trailer
Eamonn Harrison (right), 23, of County Down, who had dropped the trailer off at Zeebrugge, denies 39 counts of manslaughter with alleged organiser Gheorghe Nica (left), 43, of Basildon
Gheorghe Nica, 43, from Basildon, Essex, denies 39 manslaughter charges, but has admitted conspiracy to assist unlawful immigration.
Valentin Calota, 37, from Birmingham, and 24-year-old Christopher Kennedy, from Darkley, Co Armagh, Northern Ireland, deny conspiracy to assist illegal immigration.
Robinson, of Craigavon, County Armagh, has admitted manslaughter, conspiracy to assist unlawful immigration and acquiring criminal property.
Ronan Hughes, 40, from Leitrim, Silverstream, Tyholland, Co Monaghan, has admitted manslaughter and conspiracy to assist unlawful immigration.
The trial continues.