A mother whose son vanished during the terrorist attacks on 11 September has found him in a New York hospital.

In what may be the strangest lost-and-found case to emerge from the tragedy, the family of George Sims, 46, who has schizophrenia and amnesia, received a phone call from the health authorities this month saying they had a man in their care who fitted his description.

"He's alive, but he's not in the best of health," said his mother, Anna Sims, who lives in Newark, New Jersey. "When I saw him, he did not know me. He did not know his daughter. He did not know his brother."

Last night, another man, Albert Vaughan, 45, was reported to have come forward after being listed as missing since 11 September. Mr Vaughan has allegedly been found at a psychiatric hospital. New York city authorities say there are five other similar cases, but did not give details.

Mr Sims' illnesses mean that little is known of his ordeal. His family says he was "selling things" near the twin towers when they collapsed. He has been unable to say where he was on that day or why he vanished for so long.

Until a week ago, Mr Sims was included on lists of those lost in the attacks as "missing", if not "confirmed dead" or "reported dead". His family had never sought to declare him dead, nor had it sought compensation.