Gary Glitter must be stopped from travelling abroad when he returns to the UK, a children's charity said yesterday.

The NSPCC called on the government to ban Glitter, whose real name is Paul Gadd, from making foreign trips as a sex tourist.

His lawyer, Le Thanh Kinh, said the former glam rock star can travel wherever he wants, but intends to return to Britain.

Glitter was jailed in March 2006 by a Vietnam court for sexually abusing two girls aged 10 and 11.

NSPCC policy adviser Dr Zoe Hilton said: "It's not a done deal that he can go wherever he likes, given his record. I'd hope the authorities would make sure he does not slip off to another country. Once you're overseas you can go from country to country."

Legislation allows Foreign Travel Orders to be made against sex offenders banning them from trips overseas, but the NSPCC said these are "ineffective" because they must be renewed every six months. Each time it must be proved with new evidence that the offender poses a risk to children, and the orders only apply to one destination.

The charity also wants a better tracking system to stop them "country-hopping" and disappearing.

Dr Hilton said: "On his return to the UK, the authorities must assess the level of risk he poses to children and make sure he is carefully managed and supervised.

"We are also concerned current travel prevention orders, designed to prevent offenders from going overseas, are not working. Hardly any have been issued against sex offenders in the past five years."