A lorry driver is due to appear in court charged over the deaths of 39 migrants thought to have died in a refrigerated unit during a clandestine bid to enter the UK illegally.
Maurice "Mo" Robinson, of Craigavon in Northern Ireland, is due to appear via videolink at Chelmsford Magistrates' Court charged with 39 counts of manslaughter, conspiracy to traffic people, conspiracy to assist unlawful immigration and money laundering.
The bodies were discovered in a trailer compartment in the early hours of Wednesday on an industrial estate in Grays, Essex.
Essex Police also confirmed that a man arrested in Dublin by Irish police over an unconnected matter on Saturday "is a person of interest" in their investigation.
A spokesman said: "We are liaising with the Garda via telephone as this man is currently held outside the jurisdiction of the law of England and Wales."
Three other people arrested in connection with the deaths have been released on bail, Essex Police said on Sunday.
Detectives are now working on the largest mass fatality victim identification process in the force's history.
Police initially said the victims were Chinese, although a number of Vietnamese families have described how they fear their loved ones are among the dead.
Some of the victims are said to have paid thousands of pounds to traffickers to guarantee their safe passage to the UK, from where they would be able to carry out work that would give them money to send home.
Detectives are also investigating a "wider conspiracy" after claims surfaced that the lorry could have been part of a convoy of three carrying around 100 people.
