Two more people have been arrested in England as part of the investigation into the deaths of 39 people found in the back of a lorry in Essex, police have said.
A man and a woman, both 38 and both from Warrington, were arrested on suspicion of conspiracy to traffic people and on suspicion of 39 counts of manslaughter, Essex police said.
The arrests followed raids at addresses in Cheshire, the force added.
The 25-year-old driver of the lorry, named as Mo Robinson, from Northern Ireland, was arrested in the early hours of Wednesday and remains in custody.
Bulgarian TV has named Joanna Maher, 38, from Warrington, as an owner of the Scania lorry cab at the centre of the investigation.
She and her husband, Thomas, also 38, who is reportedly a haulage boss, told reporters they had owned the cab but sold it 13 months ago to a company in County Monaghan, near where Robinson lives.
The route undertaken by the trailer will be one of the key priorities of the cross-border investigation. The trailer was leased from one Irish company, the Monaghan-based Global Trailer Rental Europe, on 15 October to another business on the Irish border. It was the first time the second business had made such a leasing arrangement.
Sources have said that GPS data from the refrigerated unit shows that it left Monaghan on 15 October, crossed into Northern Ireland, and then back south into Ireland.
It then travelled from Dublin port to Holyhead in north Wales overnight on 16 October, before crossing to mainland Europe that evening.
The trailer travelled to Dunkirk and Lille in France, and Bruges in Belgium. Dunkirk is a 40-minute drive from Calais and is a known site for people smugglers preying on migrants seeking to cross the Channel to the UK.
The data from the tracking device, which has been passed on to Essex police investigating the deaths, also shows the trailer made two journeys between the UK and mainland Europe between 17 and 22 October.
On Thursday, police officers began moving the victims from the Port of Tilbury to the mortuary at Broomfield Hospital in Chelmsford. The first post-mortem examinations will start on Friday.
The force added: “Formal identification will then follow the coronial process and will be a lengthy but crucial part of this investigation. As our investigations continue, the picture may change regarding identification, and we will continue to provide updates when appropriate under the direction of HM Coroner.”