Truck driver Mo Robinson from Co Armagh has been charged with 39 counts of manslaughter this afternoon. He will appear tomorrow in court.

A man in his 20s has been arrested at Dublin Port in connection with the probe into the discovery of 39 bodies (eight women and 31 men) in a lorry in Essex.

Essex police have not yet confirmed the identities or nationalities of the 39 people whose bodies were found in Essex, England on Wednesday.

Police initially believed all of the dead were Chinese nationals, but the force said at a press conference "this is now a developing picture" amid reports several may be Vietnamese.

A number of people who say their relatives are among the dead say the truck was one of a convoy of three, carrying 100 migrants in total. They say two of the vehicles are thought to have completed their journeys, but the third - carrying the 39 victims - was delayed at an unknown location. These claims have not been independently verified.

Three people with Irish connections are being questioned - a 48-year-old man from Northern Ireland who was detained at Stansted Airport yesterday; a couple - named locally as haulage boss Thomas Maher and his wife Joanna, both 38 - arrested in Warrington, England.

It is not yet known when the victims entered the trailer, where temperatures can be as low as minus 25C if the fridge is activated, or the exact route it travelled.

Belgian officials said the trailer arrived at Zeebrugge at 2.49pm on Tuesday and left the port the same day en route to the port of Purfleet, Essex.

The trailer arrived at Purfleet at around 12.30am on Wednesday, and was picked up by the cab, known as the tractor, which arrived from Northern Ireland via Holyhead in North Wales on Sunday.

The lorry left the port at Purfleet shortly after 1.05am before police were called to the Waterglade Industrial Park on Eastern Avenue in nearby Grays at 1.40am.

Maurice 'Mo' Robinson, 25, has been charged with 39 counts of manslaughter over the deaths of 39 people found in a trailer in Grays, Essex, on Wednesday.

An Essex Police statement said: “The Crown Prosecution service has authorised Essex Police to charge a man in connection with the investigating the deaths of 39 people whose bodies were found in Grays on Wednesday.

“Maurice Robinson, 25, of Laurel Drive, Craigavon, Northern Ireland was arrested shortly after the discovery was made at the Waterglade Retail Park.

“He is due to appear at Chelmsford Magistrates’ Court on Monday 28 October charged with 39 counts of manslaughter, conspiracy to traffic people, conspiracy to assist unlawful immigration and money laundering.

“Three other people have been arrested in connection with this investigation.

“A 38-year-old man and a 38-year-old woman from Warrington and a 48-year-old man from Northern Ireland remain in custody.”

UPDATE 8.30pm: Detectives are sifting through more than 500 exhibits, including mobile phones, to determine the identities of the dead, Essex Police have said.

The force said in a statement: “There are 39 victims and each appears to have a bag of some description, clothes, and other belongings.

“So far we have over 500 exhibits, including mobile phones which have to be downloaded and the interrogation of mobile phones will be important for identifying the victims but also assisting the wider investigation – this needs to be done in forensic way so it will pass the evidential process for court later.

“As in any instance where a mass fatality has unfolded we cannot predict how long this process will take.”

EARLIER: Essex migrant deaths: Man arrested at Dublin Port

A man in his early 20s from the North has been arrested at Dublin Port as part of the investigation into the discovery of 39 bodies in a lorry in Essex.

The arrest was made on foot of an unrelated outstanding court order for an offence in this jurisdiction.

He will appear before the Criminal Courts of Justice this afternoon.

Update 5.20pm: An Essex Police spokesman said: “We are in liaison with the Garda police in relation to an arrest they have made today at Dublin Port. At this point (the man) is only being processed by the Garda in relation to unconnected offences to the Essex Police investigation.”

A convoy of funeral directors’ vehicles enter the Port of Tilbury to collect the bodies of the 39 people (Kirsty O’Connor/PA)

Officers had earlier arrested a couple, named locally as haulage boss Thomas Maher and his wife Joanna, both 38, of Warrington, England but who both also have Irish connections, in the course of the investigation.

Mo Robinson, 25, from Armagh the driver of the Scania truck, was arrested on suspicion of murder on Wednesday.

Dublin Port (archive picture)

Detective Chief Inspector Martin Pasmore.

EARLIER: Truck carrying 39 migrants may have been part of convoy, say relatives

Essex Police are investigating lines of inquiry to “establish whether there is a wider conspiracy involved” in the deaths of 39 people found in a lorry in Grays on Wednesday, Detective Chief Inspector Martin Pasmore said.

Mr Pasmore told a press conference at Grays police station in Essex that all of the victims had been recovered from the trailer and were now at Broomfield Hospital in Chelmsford.

Mr Pasmore appealed to the Vietnamese community to come forward if they believe a family member of loved one may be one of the victims.

He added that he cannot confirm the victims' nationalities or identities and is "remaining open minded".

He said he had met with the Vietnamese ambassador on Saturday morning as part of efforts to engage with the country’s wider community.

Although we can’t speculate at this time on the nationality of our victims, it’s clear from everybody that we are getting a large amount of engagement from the Vietnamese population, from communities home and abroad.

Meanwhile, there are media reports that relatives who fear their loved ones are among those who died believe the truck may have been one of three lorries carrying more than 100 migrants. the reports could not be independently verified at the time of writing.

According to the relatives' comments, two of the vehicles are thought to have completed their journeys, but the third - carrying the 39 victims - was delayed at an unknown location.

Asked about reports the lorry was part of a convoy of three carrying around 100 people, Mr Pasmore said: “...You’re homing straight on to an investigative question. My role is (only) to identify the deceased.

“What I will say is I know the senior investigating officer remains open minded. There are lines of inquiry that are set of course to establish whether or not there are wider conspiracies involved in this...but I can say no more than that.”