Social workers caring for the "Piano Man", who has not spoken since he was found in Kent six weeks ago, are following up clues to his identity.
Italian TV has broadcast pictures of a pianist resembling the man
The National Missing Persons Helpline has taken more than 800 calls and received 150 e-mails about the man who communicates only through music.
One lead is being pursued in Italy, where TV pictures have shown a pianist with a resemblance to the man.
The man, in his 20s or early 30s, was found in Sheerness on 7 April.
"A number of significant pieces of information" received from people worldwide are being investigated, social workers caring for him said.
He has not said a word since he was picked up by police after being found in a confused and dishevelled state.
He was wearing a soaking wet suit and tie, and all the labels had been removed from every item of his clothing.
He is being looked after in a secure mental health unit in north Kent.
The mystery man produced a pencil drawing of a piano
Police have discounted claims he is a street musician from France.
The Italian TV pictures were filmed at an instrument fair in Rimini five years ago, and although his hair is different, his nose and facial structure is very similar. He also stayed silent.
The "Piano Man's" carers at the West Kent NHS and Social Care Trust said on Thursday there had been a large amount of information put forward from people across the world.
A statement said many different names had been suggested as well as a number of nationalities.
It added that the man had undergone a range of physiological tests, and was in good physical health, and continuing to eat and drink.
His social worker Michael Camp said he believed the man may have been "tipped over the edge".
"I don't think this is somebody who was living a 'normal life' until 7 April and suffered a trauma," he said.
When he was first found, staff at the Medway Maritime Hospital gave the man a pen and paper in the hope he would write his name, but he drew a grand piano.
His carers then put him in front of an instrument in the hospital chapel and he stunned them with a virtuoso classical performance. He has also composed music since being found.
The case has drawn comparisons with the Oscar-winning 1996 film Shine, which tells the story of acclaimed pianist David Helfgott who suffered a nervous breakdown while playing.