A 72-year-old retired charity worker has been arrested on a wine-tasting holiday in South Africa on suspicion of being one of America's most wanted men.
Mr Bond was arrested and imprisoned in Durban
Derek Bond, a grandfather from Bristol, is being held in custody in Durban after he was detained at the request of FBI officials investigating fraud in the United States.
The father-of-three and his family insist it is a case of mistaken identity.
But the FBI told the BBC it believed the pensioner was Derek Sykes, a man they are looking for in connection with a telemarketing scheme which defrauded people of millions of dollars.
The Clifton-based Rotarian was arrested at gunpoint as he arrived in the country two weeks ago for the wine-tasting tour with his wife Audrey.
We're terribly upset - he's been kept in prison for more than two weeks, but it's not the fault of the South African authorities
Mr Bond's son Peter, 45, from Peterborough, Cambridgeshire, said his father's health had
deteriorated since the ordeal began.
"We believe that he is the victim of an identity fraud where some person in the United States obtained details of his identity, including his passport number, and has used them for fraudulent purposes in the US," he said.
He said Mr Bond had agreed to be extradited to the US on legal advice, in order to get the problem sorted out quickly.
"The situation is entirely unacceptable, but our immediate concern is to secure the safe release of our father," he said.
Mr Bond's daughter, Gillian, 46, from Norwich, Norfolk, flew to South Africa to join her 71-year-old mother.
She said: "We're terribly upset. He's been kept in prison for more than two weeks, but it's not the fault of the South African authorities.
"The FBI have had all the paperwork, but they don't appear to have read it until now.
"It wasn't until yesterday morning that an FBI officer was sent to speak to him."
She said a statement had only been taken from him on Monday.
Despite the family's pleas that they have arrested the wrong person, the FBI now wants to extradite Mr Bond to America.
Agent Bob Doguim, of the FBI field office in Houston, Texas, told the BBC it would take a few more days positively to identify him.
A spokesperson for the US Embassy in Pretoria said: "We are actively involved in attempting to establish whether Mr Bond is in any way identifiable with Derek Sykes.
"If he is identified as being an individual charged with fraud in the US he will be extradited, if not he will be released."
Earlier, an FBI press office spokesman said a man called Derek Bond appeared on one of their wanted lists "some time ago" for fraud-related activities in Texas.
The Foreign Office has been in contact with the British consul in Durban to try to improve conditions for Mr Bond.