One person has been arrested in Dublin Port in connection with the deaths of 39 migrants found in a lorry container in Essex on Thursday morning.
The man who is believed to be aged in his 20s is said to be from Northern Ireland.
He was arrested after getting off a ferry on Saturday afternoon and is due to appear at the Criminal Courts of Justice.
The blue Scania truck that he was driving has been impounded by gardai.
A spokesman for gardai told Dublin Live: "Earlier today 26 October 2019 at Dublin Port An Garda Siochana arrested a male in his early 20s from Northern Ireland on foot of an outstanding court order for an offence in this jurisdiction."
This comes after an Irish couple were arrested on Friday on suspicion of manslaughter after 39 people were found dead in a truck in Essex.
Joanna Maher, 38, and her husband Thomas, also 38, were arrested by UK cops as part of the huge investigation into the horror find in Essex on Wednesday morning.
Thomas is registered as the owner of the haulage firm while Dublin-born Joanna works as a hairdresser.
Last night the pair said they had sold the cab registered in the Black Sea port Varna a year ago.
It was sold to a Monaghan company near where arrested lorry driver Mo Robinson lives.
The 25-year-old was detained in custody on suspicion of murder on Wednesday after being arrested by the Scania lorry in Grays, Essex.
Essex Police are leading one of the biggest murder investigations in UK history after the discovery of the bodies of 39 migrants in a lorry on an industrial estate in Grays, Essex on Wednesday morning.
The driver of the Scania lorry, Mo Robinson, 25, has been in custody for mass murder since the bodies were found.
Police have not confirmed whether the driver raised the alarm after finding the bodies, while his supporters have set up petitions online calling for his release.
People living close to Purfleet said illegal migrants were a familiar sight.
"It's a magnet for illegals," said Janet Lilley, 61. "People would come strolling out of the docks, get in the vans and that's it, they drive off."
Lee Tubby, 45, who lives opposite the port, said he has seen people "climbing out the top and out the back" of lorries and cutting the plastic roof covering to climb through.
"We've had people just come out of the port knocking on the door asking for shoes, asking for water," he said.
It is not yet known when the victims entered the sealed refrigerated trailer, where temperatures can be as low as -25C, or the exact route it travelled.
Mike Gradwell, a former Lancashire Police detective superintendent who worked on the probe into the Morecambe Bay cockling tragedy in which 23 Chinese illegal immigrants drowned, told BBC Breakfast that those inside could have been trafficked by a Snakehead gang.
"These are criminal travel agents really - you go to a Snakehead to say you want to be trafficked to an economic opportunity and usually you'll borrow quite a significant amount of money," he said.
Belgian officials said the trailer arrived at Zeebrugge at 2.49pm on Tuesday and left the port the same day en route to Purfleet.
Joachim Coens, chief executive of Zeebrugge port, said it was unlikely people were loaded into the container at the Belgian site, while mayor Dirk De Fauw, who is also the chairman of the port, said it was "virtually impossible" the victims went into the trailer at the Belgian border.
The trailer arrived at Purfleet at around 12.30am on Wednesday, and the front section to which it was attached, known as the tractor, came from Northern Ireland via Holyhead in north Wales on Sunday.
Irish company Global Trailer Rentals Ltd (GTR) confirmed it owned the refrigerated part of the lorry and a spokesman said the company was "shellshocked" and "gutted" by the news.
The firm said the trailer had been leased on October 15 from its rentals yard in Co Monaghan, in the Republic of Ireland, at a rate of 275 euro (£237) a week.
It said it provided police with information about the person and company that leased the trailer, as well as offering to make tracking data available.
Three addresses have been searched in Northern Ireland as part of the probe, while warrants were also carried out in Cheshire.
China has called for joint efforts to counter human smuggling, while vigils have been held in London and Belfast to pay tribute to the victims.
