(Corrects 1st paragraph and headline after police re-published statement to show police believe trailer (not truck and container) had travelled from Zeebrugge, and 4th paragraph to refer to tractor unit (not trailer) and Northern Ireland (not Ireland))
LONDON, Oct 23 (Reuters) - British police said they believed the trailer from a truck found on Wednesday containing the bodies of 39 people had travelled from Zeebrugge, Belgium, into the port of Purfleet in eastern England.
It then docked in the Thurrock area at around 12:30 a.m. local time for around 35 minutes before departing, Essex Police said in a statement.
Police had originally reported that the truck, which ended up at an industrial site in Grays, about 20 miles (32 km) east of central London, had travelled via Holyhead in Wales.
They said they believed the tractor unit of the truck had originated in Northern Ireland. (Reporting by Andy Bruce and Michael Holden; editing by Stephen Addison)