A canoeist who walked into a police station five years after going missing has no memory of what happened, police have said.
John Darwin was presumed dead after the remains of his canoe were found washed up on a beach in Seaton Carew, near Hartlepool, Teesside, in March 2002.
A search at the time failed to locate Mr Darwin, then 51, who walked in to the station in London on Saturday.
Mr Darwin's 90-year-old father Ronald said it was "wonderful news".
Cleveland Police said officers were due to speak to him later.
A force spokeswoman said: "We are pleased that Mr Darwin has been located safe and well.
"This has been a long-running inquiry on behalf of the force and officers from Hartlepool hope to speak to Mr Darwin later to establish what has happened over the past five years.
"The family have been informed. We have no account of what has happened in the last five years. He walked into a police station and said 'I think I am a missing person.'
"The guy cannot remember anything about what has happened or why he has come forward.
"He has no memory at all. He has obviously been somewhere for the last five years and a lot of questions need answering."
No signs of illness
Mr Darwin's 90-year-old father Ronald, who lives in Blackhall, near Hartlepool, said: "It's wonderful. Thank the Lord.
"I always knew John wouldn't do anything stupid. He has always been a sensible sort of fellow."
Mr Darwin was examined shortly after speaking to police in London and showed no signs of illness.
He left the station with his two sons who live in Hampshire and Berkshire.
Mr Darwin's disappearance sparked agony for his family.
At the time of his disappearance he was working as a prison officer and the alarm was raised when he failed to arrive for a night shift.
'Difficult to grieve'
His wife Anne, a doctor's receptionist, said six months after her husband vanished: "People die, have a funeral, they have a headstone, there is something to mark the fact they existed on this earth.
"But without a body, I don't know how we can mark John's life.
"All I want is to bury his body. It would enable me to move on. It's difficult to grieve without bringing things to a close, but as it is I'm in limbo and there's nothing I can do."
A spokesman for the Metropolitan Police said Mr Darwin was not held in custody.
He said the Met would not be playing any further role in the investigation as Cleveland Police opened the original missing persons inquiry.