Police in Vietnam have taken hair and blood samples to get DNA from relatives of people feared to be among the 39 who died in the back of a truck near London last week.
British police are still trying to establish the identity of victims who in many cases lacked identity documents.
Police in Britain said on Saturday they had charged one man, 25-year-old Maurice Robinson of Craigavon in Northern Ireland, with 39 counts of manslaughter and other offences including conspiracy to traffic people.