Vietnam has jailed four people in connection with the deaths of 39 migrants found in a refrigerated truck in Britain last year, state media reported.

The deaths of 31 Vietnamese men and eight women in a car near London in October 2019 highlighted the risk of illegal immigration to Europe and sparked an international outcry.

A court in central Ha Tinh province on Monday sentenced the four defendants – the youngest 26 – year – old and 36 – to two and a half to seven and a half years in prison, according to the official newspaper.

They were convicted of “managing illegal immigration, brokering”, with two others given suspended sentences.

But Nugene Din Gia, who lost his 20-year-old son Lung in the crash, told AFP he believed the defendants should not have been jailed. “Those involved were just trying to help and then the accident happened,” he said. “He was an adult who made his own decision and voluntarily joined the trip, earning money to alleviate our poverty, in order to improve his life.”

Gia says her son wanted to travel from France to Britain, where he has been living illegally since 2018.

The trip to Britain, where he set out to find work at a nail salon, would cost about 11 11,000 (,000 14,000). “It’s been almost a year but it’s painful whenever I think about it,” Gia said.

Lung and most of the other migrants were from a handful of poor Madhya Pradesh. The lorry, carrying two 15-year-old boys and assistants, arrived on the morning of October 23 on a ferry from the Belgian port of Gibrug.

An autopsy showed that they had died due to lack of oxygen and excessive heat.

A number of people have been arrested and charged in Britain, France and Belgium in connection with the murder, including the driver of the lorry, Maurice Robinson of Northern Ireland, who pleaded guilty to the murder.

Ronan Hughes, 40, of County Armagh in Northern Ireland, also pleaded guilty to murder last month.