Many west African children are at risk from traffickers
A report due to be published on Monday by the UK branch of End Child Prostitution, Pornography and Trafficking (Ecpat UK) says that a growing number of foreign children are being forced into prostitution in the UK.
Report author Carron Somerset said the research stemmed from an investigation by Ecpat's west European branches into the extent of trafficking of children from eastern Europe.
Ms Somerset told BBC News Online that though there was a lot of information around about west African trafficking into the UK it had proved very difficult to find out about eastern European children.
"There's anecdotal evidence from HIV groups working with eastern European adults in the sex trade about youngsters they believe to be only 16 or 17 but who claim to be over 18.
"And the police recently picked up two Romanian girls who admitted to being only 15," she said.
Ms Somerset added that for many children Britain was just a stop on their way into sexual slavery in other western European countries such as Italy and the Netherlands.
Call for legislation
One of Ecpat's main partners, Anti-Slavery International, is calling for tougher laws to deal with traffickers.
Spokesman Mike Kaye told BBC News Online the difficulty in getting frightened children to testify was not helped by the lack of specific anti-trafficking legislation to deal with perpetrators.
Mr Kaye said: "Where charges have been brought they're charged under the Sex Offences Act 1956 and they're commonly getting between one and a half to two years.
"So when a conviction is possible you're not getting a sentence commensurate with the gravity of the crimes which have been committed."
Mr Kaye believed the Ecpat research had merely uncovered the "tip of the iceberg".
"I think it would be reasonable to conclude that you are looking at hundreds of children at the absolute minimum who have been trafficked into this country," he said.
He added that without adequate legislation and support for the victims the problem would only get worse.
'Duped'
Carron Somerset said Ecpat also wanted government assistance for campaigns to raise awareness among parents about the dangers of sending their children abroad.
"It's all about poverty. It's one less mouth to feed and if they think that child may be able to send money back and could possibly have a better life than they'll go for it.
"I think some parents know what's going to happen to their children but I think a lot are duped as well," Ms Somerset said.
She added that Ecpat hoped as well as bringing about new legislation the report would also lead to more research into the issue.