Deputy Assistant Commissioner Richard Bryan said there is no need for UK forces to adopt the American system of immediate information broadcasts.

The officer, who is the Association of Chief Police Officers (Acpo) lead on missing people, said forces already operate an effective "child rescue alert".

Mr Bryan said police would rather use other investigative techniques to trace children before going public and potentially alerting abductors.

But he admitted that guidelines may be too strict as only three alerts have been issued in the past five years.

Mr Bryan added that introducing such a system on mainland Europe would have its merits, but there are substantial legislative hurdles.

His comments will come as a blow to Kate and Gerry McCann as they campaign for a Europe-wide quick response system to help find abducted children. Their daughter Madeleine disappeared a year ago from a holiday apartment in Praia da Luz, Portugal.

France is the only country to have introduced alerts along American lines, with a similar but less well-established scheme in Belgium.

Mr Bryan said the McCanns are doing a "sterling job" in raising the issue of how police deal with child abductions.

He said: "I welcome the McCann's pressing for an amber alert. People need to realise we have got a version of amber alert in the UK - child rescue alert. That has been in place since 2003 in Sussex and it was rolled out nationally by 2006. We have only had to use it on three occasions."