The 39 people found dead at the end of October in a refrigerated truck near London were of Vietnamese nationality, UK police said on Thursday.
All the victims, 31 men and eight women, were identified and are from Vietnam, a spokesman for police in Essex, southeastern United Kingdom, told AFP, where the vehicle was found at dawn on 23 October.
In a statement, the Vietnamese embassy in London expressed its "deep sadness" about the incident, conveyed its condolences to their families and assured them of their support in returning the bodies to the country.
Initially, British police announced that they had Chinese nationality, until several Vietnamese families came forward to say they feared their relatives were among the dead.
The truck driver, a 25-year-old Irishman and another man from the same British province, were arrested in the United Kingdom and Ireland. The former was charged with manslaughter, money laundering and plot to favor illegal immigration.
Three people were arrested and released on bail. Police investigate whether more is involved. Another 11 were detained in Vietnam in connection with this same case.
Unusually in the United Kingdom, the tragedy has caused much commotion and warnings about the risk that human traffickers will increase the number of irregular immigrants in Europe.
From Hanoi, the Vietnamese Ministry of Public Security confirmed that the dead originated in six provinces of the country.
Even before official confirmation, the Vietnamese government announced earlier this week that it was working with the British authorities to repatriate the bodies.