Police say the newsflash alert - using local television and radio to give details of kidnap victims - will be a major tool in tackling such crime.

At the launch in Brighton, Sussex, the mother of murdered schoolgirl Sarah Payne welcomed the scheme and gave it her full support.

It is not something we plan to use often, but ... it will be implemented with the sole aim of finding that child - alive"

Det Supt Jeremy Paine

Sussex police will be the first force to use the system, called Child Rescue Alert, and if successful it could be introduced throughout England and Wales.

The scheme will work by newsflashes being broadcast as soon as police know a child has been snatched.

Det Chief Supt Jeremy Paine, head of the Sussex Police Crime Management Department, said action in the immediate aftermath of a child abduction was crucial.

He told BBC News 24: "Sadly, in most cases within three to six hours the child will die if we do not recover them."

But he added that the scheme was unlikely to be activated more than once or twice a year.

The one thing we learned from Sarah's case is that the police and the media can work together

Sara Payne

"It is important to realise that we are not talking about domestic abductions, unless, of course, the child's life is thought to be at risk.

"It is not something we plan to use often, but when the need arises it will be implemented with the sole aim of finding that child - alive."

Speaking at the launch, Sarah Payne's mother Sara gave her backing to Child Rescue Alert, based on an American scheme called Amber Alert.

'Opportunity'

"It can definitely work in this country. "The one thing we learned from Sarah's case is that the police and the media can work together," she said.

The question of whether the scheme could have helped find her daughter was "too painful" to consider, she added.

Convicted paedophile Roy Whiting was sentenced last December to life imprisonment for kidnapping and murdering the eight-year-old.

The little girl was taken from near her grandparents' home in West Sussex in July 2000.

Det Chief Supt Jeremy Paine said the public had shown they wanted to help in situations of child abduction.

"We have seen how the subject of child abduction has rocked the country in the last few years and people genuinely want to do something about it," he said.

Amber alert

Earlier he said the Sussex force was working hard on improving prevention - through management of registered sex offenders - and investigation of child abduction and murder cases.

But he went on: "It is the piece in the middle that is missing and it's the most important part - saving the child's life. That's where Child Rescue comes in."

Amber Alert was first introduced in Texas following the kidnapping and murder of nine year old Amber Hagerman.

Amber Alert has now been developed across 15 states in the US and is believed to have saved the lives of at least 36 children.