Facebook may relax a ban on children aged under 13 from joining its site after finding that many kids, some with their parents' permission and help, were already using it.

“There is reputable evidence that there are kids under 13 who are lying about their age to get on to Facebook,” The Sunday Times quoted Simon Milner, Facebook's head of policy in Britain, as saying. “Some seem to be doing it with their parents' permission and help,” he said.

If the ban is lifted, a flood of new users are likely to sign up to the social network, which floated on the stock market last week for $105 billion.

The number of people with profiles — now estimated at 900 million active users — will probably hit the iconic one-billion mark.

But Mr. Milner said the decision to allow children to create profiles was still at an early stage, and he would launch a debate next month on the minimum age in Britain at Wellington College, Berkshire.

“We have a strict under-13 rule because of legal issues in America. We apply the same rule all over the world. But a lot of parents are happy their kids are on it. We would like to hear from people what the answer might be,” he said.

Supporters of the minimum age believe it helps to shield children from cyber-bullying and inappropriate contact with adults.

Surveys taken in the past in the U.K. have suggested that one in three British children has been the victim of abuse on the Internet.