A man from Northern Ireland has been arrested over the deaths of 39 people found in a truck in Essex in October, police said.
The 23-year-old was arrested by the Thames Valley Police on behalf of the Essex Police.
A refrigerated truck with 39 bodies was found in Essex in October after having travelled from Belgium.
Following the discovery, the truck's driver Maurice Robinson was arrested and charged with 39 counts of "manslaughter, conspiracy to traffic people, conspiracy to assist unlawful immigration, and money laundering." Three others have been released on bail.
Police in Dublin arrested Eamonn Harrison in connection to the investigation and police said they were searching for brothers Ronan and Christopher Hughes who are wanted on suspicion of human trafficking.
Earlier this month, Vietnamese authorities told state media that they had made several arrests in connection with the case.
The 39 victims were all recently identified by police.