Police are winding down the hunt for missing schoolgirl Alex Heaman.

Detective Chief Inspector Adam Hibbert, heading the search, admitted last night: "All active lines of inquiry have drawn a blank so far.

"The operation is being scaled down in terms of the number of officers working on it but it will remain active until we have been able to establish what has happened to Alex."

It is now almost four weeks since the 14-year-old left her home.

Officers spent the weekend scouring the Brighton area in a bid to trace her.

Alex, who has not been seen since she left her home in Abergavenney Road, Lewes, on September 1, told her mother Tamsin she was going to visit friends in Brighton.

There have been several unconfirmed sightings of Alex and officers from the Sussex Police Major Crime Branch have been working round the clock to find her.

Mr Hibbert, who is leading the hunt, said: "Alex's mum and her grandparents have both made desperate appeals for her to get in touch and are praying for that one phone call that will let them know she is alive.

"We urge anyone who has seen her to contact us immediately.

"Alex is a street-wise teenager but by virtue of her age she is extremely vulnerable and it is a priority for us to find her and ensure she is safe and well.

Anyone with information should call police on 0845 6070 999, quoting Operation Warren.