British police arrested a man Tuesday on suspicion of manslaughter over the death of an Afghan Sikh immigrant whose body was found in a shipping container.

The suspect from Northern Ireland was arrested in the province and is in custody pending transfer to mainland Britain for questioning.

Fleeing alleged religious persecution in Kabul, 34 Sikhs including children aged between one and 72 were found alive on Saturday in a shipping container at Tilbury Docks in Essex, east of London, after staff heard banging and screaming.

The man who did not survive the North Sea crossing from Zeebrugge port in Belgium has been identified by police as 40-year-old Meet Singh Kapoor. His children, aged nine and 12, were in the container with him.

"Police in Northern Ireland have arrested a man on suspicion of manslaughter and facilitating illegal entry into the United Kingdom," police said.

Meanwhile police in Somerset, southwest England, said they stopped a truck with 20 people in the back and were working with the immigration authorities to establish the circumstances.

The people inside were treated by paramedics for possible dehydration but the indications were that they were all healthy.