The wreckage of John Darwin's canoe was found in March 2002 Darwin under arrest

In a statement, Anthony and Mark Darwin asked how their mother Anne could have let them believe their father was dead for five years.

Mr Darwin reappeared after disappearing in 2002 off the coast of Hartlepool in an apparent canoeing tragedy.

He was arrested by Cleveland Police on suspicion of fraud after walking into a London police station at the weekend.

'Very much alive'

Anne Darwin, 54, has admitted to newspapers that a photo of her and her husband taken last year in Panama is genuine.

Mrs Darwin sold the family home on Teesside and moved to Panama six weeks ago.

There has been no independent verification of the Mirror's photo

In the statement, released through Cleveland Police, the couple's sons said they had been through a "rollercoaster of emotion" since their father's reappearance.

They said: "Having seen the recent media speculation surrounding our parents ever since our dad was arrested, we are very much in an angry and confused state of mind.

"In the short space of time following our dad's appearance in London on Saturday, we have gone through a rollercoaster of emotion.

"From the height of elation at finding him to be alive to the depths of despair at the recent stories of fraud and these latest pictures. And the shock of being thrust into the media spotlight.

"If the papers' allegations of a confession from our mam are true then we very much feel that we have been the victims in a large scam.

"How could our mam continue to let us believe our dad had died when he was very much alive?"

Mr and Mrs Darwin's sons said that they had not spoken to either of their parents since their father's arrest.

Declared dead

Cleveland Police said detectives had been given the go-ahead to interview Mr Darwin.

A police spokeswoman said: "John Darwin has been medically examined and has been declared fit for interview."

The spokeswoman said that officers had until just before midnight on Thursday to question him, after which time a superintendent's extension could be granted for a further 12 hours.

Mrs Darwin told newspapers that her life had become a "nightmare" and confirmed the picture did show her husband, who was officially declared dead in 2003.

She told the Daily Mirror, which originally published the image: "Yes, that's him. My sons will never forgive me.

"They knew nothing. They thought John was dead. Now they are going to hate me."

Mr Darwin, 57, was arrested on suspicion of fraud at his son Anthony's home early on Wednesday morning. He is currently at Kirkleatham Police Station.

Earlier Cleveland Police issued a worldwide appeal for information about Mr Darwin.