A 48-year-old man has become the fourth person linked to Northern Ireland to be arrested in connection with the discovery of 39 bodies in a lorry in Essex.
The man, believed to be from Co Armagh, was arrested yesterday at London Stansted Airport on suspicion of manslaughter and conspiracy to traffic people.
His detention came as Essex Police said the 25-year-old driver of the lorry, Mo Robinson from Laurelvale, Co Armagh, was continuing to be held for questioning on suspicion of murder.
Husband and wife, Thomas and Joanna Maher, both aged 38 and understood to be originally from the Irish border region, were arrested yesterday at their home in Warrington, Cheshire, on suspicion of manslaughter and conspiracy to traffic people.
They have been named by Bulgarian press as the owners of the lorry cab at the centre of the investigation, but the couple said they sold it to a firm in Co Monaghan in 2018.
The Irish News understands the four people in police custody are known to each other through the haulage business.
The victims, 31 males and eight women, were discovered in the refrigerated lorry trailer in the early hours of Wednesday morning when emergency services were called to an industrial estate in Grays, Essex.
Essex Police initially told reporters they believed the victims were Chinese nationals, however is now thought that up to six of the deceased may be from Vietnam.
The family of 26-year-old Pham Thi Tra My said she last contacted them on Tuesday by text messages in which she said she couldn't breathe, and wrote "I'm dying".
They said a sum of £30,000 was paid to smuggle her into the UK, and that her last known location was Belgium.
The lorry container containing the bodies had arrived at the English port of Purfleet after departing Zeebrugge in Belgium on October 22.
Another suspected victim is Nguyen Dinh Luong, aged 20, whose family say he left Vietnam a year ago and had since spent time in France.
Speaking at a press conference last night, Essex Police Deputy Chief Constable Pippa Mills said: "We owe it to those who died to get this investigation right, and speculation is not helpful. It may even hinder our investigation in its progress."
She said the force would not be commenting further on the nationalities of the victims as they continue what has become the largest murder investigation in its history.
