A theory that the so-called Piano Man could be Czech musician Tomas Strnad is a significant lead, the health trust which is caring for him has said.
The unidentified man was found in a soaking wet suit
A drummer who claims he and Mr Strnad played in a tribute rock band is said to be "convinced" he is the man found wandering streets in Sheerness, Kent.
The West Kent NHS Trust said it would now bring in a Czech interpreter.
The man, found soaking wet in a black suit on 7 April, has never spoken to carers but is a virtuoso pianist.
The National Missing Persons Helpline said Strnad was just one of 250 names being investigated.
The man, who is in his 20s or 30s, stunned his carers with a four-hour concert-standard piano performance after producing detailed pencil drawings of a grand piano.
The man is being held in a secure mental health unit in Dartford, where an upright piano has been installed in his room and doctors are considering using music and art therapy to try to communicate with him.
The drummer Klaudius Kryspin, who says he played with Mr Strnad in the band Ropotamo, has not seen him for nine years.
"When I saw the picture in the newspapers, I knew it was Tomas," he is reported to have said.
A health trust spokesman said: "The information that has been well-documented in the weekend's press has been passed to the trust and it plans to ensure it is investigated thoroughly.
"The trust is grateful for the help it has received.
The mystery man produced a pencil drawing of a piano
"Where necessary the trust will use official channels to complete this work. This process may take some time.
"At this stage it is not possible to confirm the identity of Mr X but it is fair to say this is a significant lead."
A spokeswoman for the missing persons helpline said: "We have heard about this chap but we have had 250 names suggested to us so it's just another one that we have got to look into.
"Everybody [the media] is excited about this but we don't know until we look into it properly.
"We have lots of possible names we are going through.
"No one of these is standing out at the moment. Many of them could be plausible."
More than 1,000 people from across the world have contacted the special helpline.