Strong response to new Milly appeal

But they would not reveal whether they believed any significant new leads had developed.

A police spokeswoman said: "We are delighted with the response. We will concentrate on working our way through the calls."

Police are still trying to trace anyone who saw the 13-year-old before she disappeared on 21 March from Walton-on-Thames in Surrey.

Officers believe seven people who were caught on CCTV footage on Station Avenue, where the teenager was last seen, may hold crucial information.

Milly's disappearance sparked a UK-wide police investigation.

Detectives received about 100 calls within 24 hours of relaunching the appeal.

'Not optimistic'

Detectives believe the witnesses may not have come forward because they did not realise their significance to the inquiry.

Police want to hear from a man wearing a light top and carrying a black guitar case, who was walking along the road at 1604 BST.

A blonde woman in dark trousers and top was seen two minutes later.

A group of four people, possibly girls, were seen minutes after her, as well as a cyclist riding past.

Detectives have sent the video to the FBI in an attempt to get clearer images.

However, Detective Chief Superintendent Craig Denholm, of Surrey Police, said he was "not optimistic" the extra forensic analysis would make the pictures any clearer, because British experts had already tried.