A Northern Irish man is facing multiple counts of manslaughter charges in relation to the discovery of 39 bodies in the back of a truck near London last week, Irish broadcaster RTE said on Friday.
Eamon Harrison, 23, appeared in court after the endorsement of a European Arrest Warrant, RTE said.
Neither Irish police nor Essex Police, the British force in charge of the investigation, had any immediate comment.
The RTE report said Harrison was accused of driving the trailer of the truck to Zeebrugge in Belgium before it later traveled to Britain. The bodies were discovered in the trailer in a nearby industrial estate after it was picked up at docks on the River Thames.
On Monday, the man who allegedly drove the truck to its final destination appeared in court also accused of manslaughter, money laundering, conspiracy to traffic people and conspiracy to assist unlawful immigration.
Earlier on Friday, British police said they were hunting two brothers from Northern Ireland who were described as being crucial to their investigation.