Suspects connected to the deaths of 39 migrants smuggled into the United Kingdom said that they pretended the lorry container was filled with "cookies and biscuits", according to the Belgian federal prosecutor.
The 31 men and eight women suffocated rather than freezing to death as previously suspected, Belgian authorities said, despite not issuing an official confirmation.
A 23-year-old Northern Irish driver of the vehicle allegedly told port authorities in Zeebrugge that the 'cookies' did not need refrigeration, the Het Nieuwsblad reported on Monday as quoted by the Telegraph.
Belgian federal prosecutor Eric Van der Sypt reportedly said that a final emergency text message from a suspected victim was sent two hours before the container was received in Essex.
"We are also looking for those responsible for this drama," Mr Van Der Sypt told Belgian news.
He added: "We suspect that even more people are involved. It is quite possible that the driver did not know what he was transporting."
One suspect, Mo Robinson, was charged with allegedly picking up the container in Purfleet. Mr Robinson has been charged with 39 counts of manslaughter and will appear at the Old Baily on 25 November for a hearing.