The 39 migrants found dead in the back of a lorry in Essex are all believed to be Vietnamese nationals, Essex Police has said.
Essex Police Assistant Chief Constable Tim Smith said the force is in contact with the Vietnamese government.
"At this time, we believe the victims are Vietnamese nationals, and we are in contact with the Vietnamese government," he said.
"We are in direct contact with a number of families in Vietnam and the UK, and we believe we have identified families for some of the victims whose journey ended in tragedy on our shores.
"The confirmatory evidence needed to formally present cases to HM Senior Coroner for her consideration has not yet been obtained."
He said that the force would not be able to announce the identity of any of the victims at this time.
Mr Smith added: "We will continue to co-operate closely with the Vietnamese Government, and others, to identify the victims and offer our support to all those affected by this tragedy.
"From the outset, our thoughts have been and remain with those who have lost loved ones in this tragic incident."
It comes as police in Vietnam said they have arrested two people on suspicion of involvement of the deaths of the 39 victims.
After 10 Vietnamese families reported their relatives missing, fearing they were among the victims, Ha Tinh regional police launched a criminal investigation into suspected human trafficking, a statement posted on their website said.
Two people have been arrested and others brought in for questioning, it said.
The investigation is also expected look at similar incidents that occurred over the last five years.
