The British government is under pressure over conditions at the site at Manston in Kent, which is operating at more than double its capacity, with people staying much longer than the intended 24-hour period and sleeping on mats on the floor.
Immigration minister Robert Jenrick said the numbers at the site had fallen "substantially" on Tuesday and would continue as work continued to move migrants to other accommodation.
Two British newspapers reported on Wednesday that a group of about 40 migrants from Manston were dropped at a coach station in central London on Tuesday. They reported that while about 30 had family or friends they were able to contact to stay with, 11 were left with no accommodation and were helped by a charity worker.
They cited a British Transport Police spokesperson who said police had responded to reports of a group of asylum seekers looking for assistance at Victoria station late on Tuesday.
"Officers engaged and liaised with charity partners, rail staff, and government colleagues to help them find accommodation for the evening," the spokesperson was quoted as saying.
A Reuters photographer outside the Manston processing centre said three Afghan men who said they were taken to London on Tuesday but left with nowhere to stay returned to the site in Kent on Wednesday evening as they had no other shelter.
The Home Office, Britain's interior ministry, did not have an immediate comment.
(Reporting by Henry Nicholls, Writing by Kylie MacLellan, Editing by William Maclean)
