A group of 12 UK police officers and staff has been in Vietnam to investigate the deaths of 39 migrants found dead in a truck in Essex, England in October, 2019.

The delegation came to Vietnam to meet the families of the victims, BBC reported.

British police continue investigating the death causes. Photo: AP

According to Essex police, they will be in the country until the end of February and are working closely with the British Embassy and National Crime Agency (NCA) international liaison staff in Hanoi, and the Foreign and Commonwealth Office, who have assisted with the arrangements for this trip.

Specialist officers from the NCA and officers from the Vietnamese Ministry of Public Security will be joining the Essex Police team on the visits.

On Tuesday [February 11], Essex police revealed a preliminary cause of death had been given as a combination of suffocation and overheating in an enclosed space.

The victims, including eight women, came mostly from the central provinces of Nghe An and Ha Tinh.

Further arrests have also been made in connection with the investigation.

On February 9, a 22-year-old man was arrested in Northern Ireland on suspicion of manslaughter and facilitating unlawful immigration. He is currently in custody in Essex.

Eamonn Harrison, 23, of Mayobridge, County Down, is facing 39 charges of manslaughter as well as conspiracy to traffic people and conspiracy to assist unlawful immigration.

The lorry driver Maurice Robinson, of Craigavon, County Armagh, admitted conspiring to assist illegal immigration and acquiring criminal property at the Old Bailey in November.

His co-accused, Christopher Kennedy, 23, from Darkley, County Armagh, denied conspiracy to commit human trafficking offences, assisting unlawful immigration and arranging to facilitate the travel of other people with a view to exploitation.

Meanwhile, Gheorghe Nica, 43, of Mimosa Close in Langdon Hills, Essex, will next appear at The Old Bailey on March 16.