The only air vent on the lorry was allegedly closed by the driver

Customs and Excise officers found 54 men and four women suffocated in the airtight lorry container which had made a six-hour ferry crossing from Zeebrugge in Belgium to Dover in Kent on 18 June last year. Two men survived.

Lorry driver Perry Wacker, 32, of Rotterdam, Holland, is standing trial for 58 counts of manslaughter and for attempting to smuggle people into the UK illegally from the Belgian port of Zeebrugge.

Chinese interpreter Ying Guo, 29, of South Woodford, Essex, denies conspiracy to smuggle immigrants into Britain.

'Short of breath'

Mr Hickman, giving evidence on the ninth day of the trial at Maidstone Crown Court, said the immigrants would have had a maximum of five-and-a-half hours' air supply, which would have been used up more quickly as panic set in.

Mr Wacker is accused of having shut the only air-vent on the side of the lorry container before boarding the ferry at Zeebrugge.

The court heard that there was evidence that the immigrants had attempted to rip off a wooden panel over the lower grill of the vent from inside the lorry.

Mr Hickman said: "The occupants of the container would clearly notice being short of breath long before death and once panic sets in the amount of oxygen they would require would increase.

"An attempt had been made to break the wooden panel and open circulation through the lower vent.

"This would have given good circulation through the lower vent," he said.

The case continues.