About 40 migrants were transported out of Manston, the overcrowded processing centre, on Tuesday so they could stay with friends and family in the capital, a homeless charity volunteer said.

But 11 of them had nowhere to go after reaching Victoria railway station.

The BBC has contacted the Home Office for comment.

The government has faced criticism after reports that Manston was holding migrants, including families, for four weeks, in breach of the law. It is intended people stay for no more than 24 hours while their claim is processed.

At most, 1,600 migrants should be at the processing centre at any one time - the MP for the area said that figure was more like 4,000 on Monday.

The BBC has spoken to one migrant who says he was left stranded at Victoria station on Tuesday night.

John - not his real name - said he spent 21 days at Manston, sleeping on a mattress in a tent with about 150 people.

He referred to the processing centre as a "detention centre" and said he had no phone and no access to the outside world.

John thought he was being sent to a hotel in London when he boarded the coach from Manston on Tuesday afternoon. It was once he was told to get off the coach at Victoria station that he realised he would not be going to a hotel.

"When we got to Victoria station the bus driver told us to get off the bus. I asked the bus driver to please call the immigration officer, but he said that I must get off the bus and call family. I said to him maybe there was misunderstanding because I don't have family in here.

"Other guys saying same. We were about 11 who didn't have anywhere to go. The bus driver just said we had to get off the bus. He said he just had to take us to Victoria and we should use phones to call family.

"At Victoria station I didn't know what to do. Other guys went to their families but where should I go?"

John, who did not want to say where he was from, explained a "charity guy" happened to be at the station, and saw the situation unfold.

Danial Abbas, a volunteer with Under One Sky charity, spotted the group. He told the BBC he saw a group of confused and disorientated men trying to flag down members of the public and staff at Victoria station on Tuesday evening.

The men, who he understood to be from Afghanistan, Syria and Iraq, were all wearing identity bracelets with QR codes on their wrists. They appeared to have been issued by the Home Office, Mr Abbas said.

One of the migrants shows their wrist band

"It was cold. Half of them didn't even have a jacket or proper shoes on. They were wearing flip flops. All their personal belongings were in blue plastic bags," said Mr Abbas.

They were hungry and without any money, "desperate for tea, coffee, soup", Mr Abbas said. He arranged to buy food at McDonald's and bought more than 80 items of clothing for the group from Primark - including gloves, shoes, hats and pants.

"They thought they were going to a hotel in London and were very happy about the prospect of leaving Manston," said Mr Abbas.

There have been a number of cases of diphtheria - a highly contagious bacterial infection - reported at the processing centre.

Mr Abbas sought assistance from charity Migrant Help. He was then able to get in touch with an official from the Home Office, who he says described the situation as "completely unacceptable".

The group was eventually picked up at about 01:00 GMT on Wednesday and taken to a hotel in Norwich, he said.

The British Transport Police said officers arrived at the station just after 22:30 on Tuesday night, responding to reports of asylum seekers looking for assistance.

"Officers engaged and liaised with charity partners, rail staff, and government colleagues to help them find accommodation for the evening," a spokesperson said.

They said no criminal offence was committed.

Migrant Help, which is a charity appointed by the Home Office to provide asylum seekers with advice and help with problems, said they would not comment on individual cases.

But it said it was concerning and "if this was indeed the case then, of course, our sympathies go to the people who have been put into this situation through no fault of their own".