A 38-year-old man and a 38-year-old woman from Warrington have been arrested on suspicion of conspiracy to traffic people and on suspicion of 39 counts of manslaughter.
A 25-year-old man, the driver of the lorry, remains in custody on suspicion of murder.
A warrant of further detention was granted yesterday by local magistrates.
Last night police the movement of the victims from the Port of Tilbury to the chosen mortuary site at Broomfield Hospital in Chelmsford.
This is all being done in close liaison with HM Coroner and police continue to work to ensure that the dignity of victims and respect for their loved ones are at the forefront of our investigation.
The first post-mortem examinations will begin today
Formal identification will then follow the coronial process and will be a lengthy but crucial part of the investigation.