Images released by the Home Office show how four Albanians were squashed into a tiny compartment in a van so they could be smuggled into the UK.
The four men were discovered by Border Force squeezed into a Mercedes Sprinter filled with suitcases and tyres.
Two men have now been jailed for their “blatant attempt” to smuggle them into the UK.
The van was stopped on the morning of February 23 by officers at the UK controls at the entrance to the Channel Tunnel in Coquelles, France.
It was being driven by Liviu Codreanu, who was travelling alongside passenger Constantin Rusu, the Home Office said.
When officers searched the vehicle they found a false bulkhead that had been screwed in place between the rear passenger seats and the cargo area.
There was just enough room inside the concealment for the four Albanian men to stand upright.
Ian Hanson, Border Force director Europe and international, said: “We are working around the clock with law enforcement to make sure that people smugglers face the full force of the law.
“This was a blatant attempt to try and bring people into the UK illegally. The van had been adapted for the sole purpose of smuggling.”
Codreanu, 28, and Rusu, 19, both Romanian nationals, were arrested and the investigation was passed to officers from Immigration Enforcement’s Criminal and Financial Investigation (CFI) team.
When Codreanu was searched officers found three screws matching those used in the false bulkhead in his pocket.
Codreanu and Rusu admitted charges of assisting unlawful immigration to the UK at Canterbury Crown Court on March 31.
At the same court on Tuesday, Codreanu was sentenced to 36 months imprisonment and disqualified from driving for three-and-a-half years, and Rusu was sentenced to 24 months imprisonment.
Deputy Director David Fairclough, from the CFI team, said: “No consideration had been given to the safety of the men hidden inside the cramped partition. There was a very real risk of serious injury.
“Codreanu and Rusu have rightly been handed custodial sentences. The message is clear, if you are involved in immigration related criminality, you will be caught and the consequences will be severe.”