39 Vietnamese immigrants were found dead inside a sealed truck trailer. A Romanian man has admitted manslaughter in their deaths.
The victims, including 10 teenagers, were discovered in Essex in 2019.
Marius Mihai Draghici also admitted one count of conspiracy to assist unlawful immigration at a hearing at the Old Bailey.
The 50-year-old was remanded in custody and told by Judge Richard Marks KC that his sentencing would take place later.
On October 23, 2019, after the lorry had taken a boat from Zeebrugge, Belgium, to Purfleet on the Thames estuary, the bodies of the 39 victims were discovered in Grays.
Ten teenagers were among the dead.
An inquest heard their medical cause of death was asphyxia and hyperthermia, as temperatures rose in the back of the sealed lorry container and oxygen levels dropped.
Four men have been previously jailed over the deaths.