A group of suspected illegal immigrants who had been in a container for nearly three weeks were "saved from death" by sharp-eared dock workers.
The men were found at Tilbury Docks
The four men were found at Tilbury Docks in Essex after the container was unloaded from a ship.
Essex Ambulance Service said the four were in squalid conditions and three found to be badly dehydrated.
The container was to be stored and an ambulance spokesman said they could have died if they had not been heard.
Dockers were alerted to the plight of the men when they heard cries from inside a container.
Ambulance service manager, Steve Brant, said: "We understand the container had come from Nigeria and was due to stand in Tilbury for a period before being shipped out to Amsterdam.
"It is not certain, but the four men may have been in the container for between two and three weeks. Had the port workers not heard them they would almost certainly have died.
"The conditions that greeted the ambulance crews in the container were dreadful.
"The men had taken limited food supplies but these were fast going off and sanitary conditions were awful.
"They would not have survived much longer."
The men are thought to be in their 20s and three required treatment at Basildon Hospital but have since been discharged.
All four men have been handed over to the Immigration Service.
A Port of Tilbury police spokesman said the men had told officials they were from Liberia and had applied for asylum.