Two people were found guilty on Monday of manslaughter and people smuggling over the gruesome discovery of 39 dead Vietnamese migrants in the back of a lorry in England last year.

The bodies of the men and women were found inside a sealed container near London in October 2019 after suffocating in sweltering temperatures.

Lorry driver Eamonn Harrison, 24, from Northern Ireland, and Romanian national Gheorghe Nica, 43, were found guilty on of 39 counts of manslaughter by a London court.

They are expected to be sentenced early in January.

Christopher Kennedy, 24,and Valentin Calota, 38, were also convicted for their part in the smuggling operation after the 10-week trial.

All four were found guilty over their roles in a lucrative smuggling ring which prosecutors said had been motivated by greed.

Home Secretary (interior minister) Priti Patel said Monday's verdict had motivated her "to do all I can to go after the people smugglers who prey on the vulnerable and trade in human misery".

"I'm determined to bring callous people smugglers to justice and keep our communities safe from the actions of horrendous organised crime groups."

Monday's convictions brings the total number found guilty in the UK in connection to the crime to eight.

Prosecutors are considering charges against a further three people.

Maurice Robinson, 26, who collected the container and found the bodies, had already pleaded guilty to 39 counts of manslaughter and to conspiring in people-smuggling.

Haulage firm boss Ronan Hughes, 41, has also admitted 39 manslaughter charges.

A total of eight people have been convicted in connection with the discovery of Vietnamese migrants in the back of a lorry in England
A total of eight people have been convicted in connection with the discovery of Vietnamese migrants in the back of a lorry in England AFP / Ben STANSALL

The bodies were discovered at the southeastern English port of Purfleet after being sealed inside the container for at least 12 hours, in unbearably high temperatures.

A forensic expert calculated it would have taken about nine hours for the air to turn toxic in the trailer, with death coming soon after.

The victims were all aged between 15 and 44.

Prosecutors have said the trapped Vietnamese were unable to get a phone signal inside the container, whose cooling system was turned off.

Mobile phones recovered from the bodies of the 39 victims showed they had tried to raise the alarm and left messages for the families as they ran out of air.

Others had used a metal pole to try to punch a hole through the roof or attract attention, the court heard.

During the trial, British police officer Jack Emerson described finding the trailer "full of bodies" when he first arrived on the scene and searched for signs of life.

He said he was unable to check if all of those inside were still alive, as they were "closely packed" in the back of the truck.

The deaths of the Vietnamese victims in the UK have highlighted the vast and unscrupulous trafficking networks spanning the globe.

Many of them had come from poorer regions of Vietnam with their families, and like others, were plunged into thousands of dollars of debt to people smugglers to pay for the dangerous journeys.

Seven individuals were convicted in September in Vietnam for varying degrees of involvement in the trafficking in the country's central Ha Tinh province.

Investigations in France and Belgium also led to dozens of suspects being charged following an investigation led by the EU's law enforcement cooperation agency Eurojust.