There are no definite leads on the identity of the so-called Piano Man despite 500 members of the public contacting a special helpline, his social worker has said.

The name and background of the man, who does not speak but who stunned carers by giving a four-hour virtuoso piano performance, remain a mystery after one possible link to Sussex was ruled out.

He has not uttered a word since police picked him up wandering aimlessly near the beach in Minster on the Isle of Sheppey, Kent, in the early hours of April 7, wearing a dripping wet suit and tie.

All efforts to communicate with the shy and agitated man, who is in his 20s or early 30s, have failed, leaving experts baffled as to his identity.

Bizarrely, all the labels from his clothes had also been removed, making it even harder to find out who he is.

Staff at Medway Maritime Hospital in Gillingham gave the mystery man a pen and paper in the hope he would write his name or draw his country's flag.

Instead, he drew highly detailed pictures of a grand piano, showing not only the keys but also the intricate inner workings of the instrument.

When his social worker, Michael Camp, showed him a piano in the hospital chapel, he played classical music "beautifully".

Since then, he has written music, but remains mute.

Mr Camp said: "The National Missing Persons Helpline has received over 500 calls.

"We haven't got any definite leads at this precise moment and we need to sift through the information."

He said one lead that the Piano Man might be someone from Sussex had been investigated and discounted.

He said: "I have followed that up and that is a definite No. The person, at the time they phoned in, only had a verbal description from the radio.

"Once they saw a photo it wasn't the person they thought it was."

A spokesman for West Kent NHS Trust said the public response to their appeal had been "overwhelming" and due to the "sheer volume" of information they did not expect there to be any news on the mystery man's identity for 48 hours.

He said: "Mr X continues to be cared for by the Trust and there has been no change in his condition."

Anyone with any information about his identity should call 0500 700 700.