LONDON, England (CNN) -- A British man who reappeared five years after he was thought to have drowned in a canoeing accident has been arrested on suspicion of fraud, police confirmed Wednesday.
Darwin was arrested late Tuesday in the southern English county of Hampshire.
Police, who are trying to piece together the movements of John Darwin over the last five years, have made a public appeal for information over his whereabouts.
They are also investigating the authenticity of a photo published in British tabloid newspaper the Daily Mirror, which claims to show Darwin alongside his wife in an apartment in Panama City, Panama in July 2006.
The 57-year-old was presumed dead in 2002 after he went missing after going canoeing in the North Sea off the coastal town of Seaton Carew, in northeast England.
In an appeal for public help, Detective Superintendent of the Cleveland Police, Tony Hutchinson, said: "There will be people out there who know exactly where he has been, what he has been doing and where he has been living." Watch the police request for information on Darwin. »
Hutchinson said police reopened the investigation into the disappearance three months ago, when information about Darwin's finances came to light.
"One side is that he has suffered amnesia, but the other side is that some criminal case has occurred," he said.
Darwin, a prison officer and former teacher, was declared dead by a coroner in 2003, 13 months after he went missing.
But on Saturday Darwin walked in to a police station in central London and told officers: "I think I am a missing person", a spokeswoman for Cleveland Police, the local force investigating the case, told CNN.
Hutchinson said he appeared to be "in apparently good health -- tanned and well-nourished."
According to widespread media reports, Darwin told police that he did not remember where he had been for the last five years.
He was later reunited with his two sons, Mark, 31, and Anthony, 29, who released a joint statement saying the reappearance of their father was "a huge shock."
The statement said their mother, Darwin's wife Anne, who is believed to have moved to Panama last month after selling the couple's home in Seaton Carew, had also been informed of the news and "was delighted to hear it."
"We have spoken with John and he appears to be in good health, however he currently has no memory of events since June 2000," his sons said in the statement.
Darwin was arrested late Tuesday by police in the southern English county of Hampshire where he had been staying since his reappearance, police told CNN.
He is to be taken from London to the northeast for questioning later Wednesday.
Inspector Andy Vickers, of Cleveland Police, the local force investigating the case, said: "A 57-year-old man has been arrested by police in Hampshire at the request of Cleveland Police in relation to the ongoing investigation into the disappearance of John Darwin in 2002."
Darwin's 90-year-old father Ron said the last time he saw his son was just a few days before he went missing, he told his local newspaper, the Hartlepool Mail.
"The people were in to put in a television and he was round for a chat, but the house was full. He said 'tell you what dad, see you later,' and I said 'cheerio' and that was the last time I saw him," the newspaper reported the father as saying.
His father said he was looking forward to seeing his son and giving him "a nice hug and kiss." E-mail to a friend