Police investigating the deaths of 39 Vietnamese nationals found dead in a lorry trailer in Essex have arrested a 23-year-old man from Northern Ireland.
The man was arrested by officers from Thames Valley Police on behalf of Essex Police in the early hours of Friday morning on the M40 in Beaconsfield, Buckinghamshire.
He was arrested on suspicion of conspiracy to traffic people and conspiracy to assist unlawful immigration.
He remains in police custody.
The bodies of eight women and 31 men were found in a refrigerated trailer attached to a lorry in an industrial park in Grays in last month.
Maurice Robinson, a 25-year-old lorry driver from Northern Ireland, has been charged with 39 counts of manslaughter, conspiracy to traffic people, conspiracy to assist unlawful immigration, and money laundering.
A second man, Eamonn Harrison (22), was charged with 39 counts of manslaughter, along with human trafficking and immigration offences after being arrested in Ireland. Essex Police have started extradition proceedings to bring him to the UK.
Detectives have urged Ronan Hughes (40) and his brother Christopher (34), said to have links with the road haulage and shipping industries, to hand themselves in for questioning. The brothers are from Co Armagh.