Fourth Person Arrested In Connection To UK Truck Deaths

Police investigating the gruesome discovery of 39 bodies in the back of a truck east of London earlier this week have arrested a fourth person over the deaths.

A 48-year-old man from Northern Ireland was arrested at Stansted Airport on suspicion of conspiracy to traffic people and on suspicion of manslaughter, Essex Police said on Friday.

Earlier, a man and a woman, both aged 38, were arrested during raids in Cheshire, about 300 kilometres from where the bodies were found in Essex.

They remain in custody on suspicion of conspiracy to traffic people and on suspicion of manslaughter.

A 25-year-old man, the driver of the lorry in which the bodies of the 31 men and eight women were found, also remains in custody.

A local magistrate granted police a warrant to extend his detention period on Friday.

The lorry driver has not been formally charged with any offences.

Deputy Chief Constable Pippa Mills said police are working around the clock on what is a "fast-moving investigation" that is "dedicated to finding out the truth about what happened".

Mills added police would not be drawn into speculation about the nationalities of those who have died.

Police initially revealed all 39 people found dead were believed to be Chinese nationals but a Chinese Foreign Ministry spokeswoman said the nationalities had not yet been identified.

A human rights advocate based in Vietnam said at least one of the deceased might have been Vietnamese.

“We gave an initial steer ... on nationality however this is now a developing picture," Mills said, adding police will not be commenting until formal identification has taken place.

“I strongly urge journalists and people on social media not to speculate about the identities of those involved or the circumstances surrounding this investigation."

On Thursday, investigators began removing the bodies of some of the victims from the truck and transporting them to a hospital for identification.

The first post-mortem examinations to determine their exact cause of death were expected to begin on Friday,  before formal identification of the victims can begin.

Police have warned this would be a lengthy process.

"This is all being done in close liaison with HM Coroner and we continue to work to ensure that the dignity of victims and respect for their loved ones are at the forefront of our investigation," police said.

Authorities are still trying to piece together exactly where the group came from and how they died, but it's been reported that investigators now believe the group were already sealed inside the container when it left a small port in Belgium and ended up in Essex.

China's embassy in London said it had sent a team to Essex as China called on Britain to seek "severe punishment" for those involved in the deaths, Reuters reported.

Candlelight vigils have been held in the UK for the victims overnight as local authorities continue to work on the largest murder investigation in history for Essex Police.