A stag party reveller was rushed to hospital after being found unconscious and semi-naked on the floor of a Eurotunnel train.
Police and paramedics were called when the 27-year-old was discovered on the upper level of the shuttle at Folkestone, Kent, on Tuesday morning.
Witnesses said the man was dragged out of a car and left lying as the vehicle drove off.
He blocked the exit for other cars which had to reverse back down the train to get off.
The man was taken to the William Harvey Hospital in Ashford and treated for alcohol-related symptoms.
One witness said: “There was some sort of massive row and the driver ran around to the passenger side and pulled this guy out.
“As soon as the car pulled away, he collapsed on to the floor, stopping everyone getting off the train for an hour or so.”
A Eurotunnel spokesman said: “He was discovered during unloading at Folkestone.
“He was alone and we had no information of the vehicle he was in or any passengers who may have been with him.
“Police took charge and this incident only caused a minor operational incident for us.”
The company added that the incident was related to a stag party.
Kent Police said: “The initial report to us at 6am on 3 June 2013 was that there was a naked man on an inbound train.
“When located he was wearing trousers and socks but nothing on the top half of his body.
“It was established he was a passenger in a car and aged 27.
“He was taken to the William Harvey Hospital in Ashford to be treated for symptoms believed to relate to his consumption of alcohol.”