A 25-year-old lorry driver charged with manslaughter over the discovery of 39 bodies in the back of his vehicle container has pleaded guilty to assisting illegal immigration and acquiring criminal property.
Maurice "Mo" Robinson, from Northern Ireland, did not enter a plea for his other 41 charges, which include 39 of manslaughter.
He appeared for the court hearing on Monday via a video link from Belmarsh Prison in London, where he has been detained.
There is currently no date for a trial scheduled; however, Robinson is next due to appear in court in mid-December.
The 39 victims, all Vietnamese nationals, were found in the back of a refrigerated lorry container in an industrial park in Essex in October.
Robinson is among three people who have been arrested in Ireland and the UK, and several other arrests have been made in Vietnam.
Three others have been released on bail pending further investigation in the case.
It is a case that has since brought a spotlight to human trafficking cases across Europe, with several reported since the grisly discovery.
Last week, more than a dozen migrants were found in the back of a lorry aboard a ferry travelling from France to Ireland.
The migrants were all described by authorities to be in "good health", and undertook medical assessments upon arrival in Ireland.