Derek Bond had wondered if he would survive prison

Charity worker Derek Bond told a news conference at Heathrow he had come "close to the edge" during his ordeal.

The 72-year-old Bristol grandfather was arrested at gunpoint during a holiday to South Africa, and held in prison for three weeks, in a case of mistaken identity.

He repeated his furious criticism of the FBI for their lack of action during his time in prison, saying his opinion of the US authorities was "pretty low, I can tell you."

My file went in the in-tray and nothing happened for a very long time Derek Bond

"A lot of the time I spent in South Africa was because they were vacillating and would not move to do anything," he said.

"My file went in the in-tray and nothing happened for a very long time...

"It was only when the media were alerted to this that something started to happen."

Although he had no criticism of the South African police, he said he nonetheless found it extremely hard to cope during his time awaiting extradition to the US.

"I just had this knot in my stomach... I was put into a large cell with murderers, rapists, drug addicts, and we were held in a cage.

Mrs Bond had had to cope alone while her husband was in prison

"My spirits just started to sink and sink and sink, I wondered at one stage if I was going to survive."

Mr Bond, who has previously threatened to sue the FBI, said this remained his position: "I think something must happen."

The couple's daughter Gillian Bond said: "The decision has to be his, but personally I hope he does.

"He has been through so much, we all have. It has been extremely hard for my mother, but that is nothing compared to what my father has been through.

"I should be happy this morning, but I am still just so angry about it all."

Watching the press conference, Mr Bond's solicitor Andrew Gregg said the pensioner would need a good rest.

DEREK BOND'S ORDEAL Jan 27 Questioned on arrival in South Africa Feb 6:Arrested at KwaZulu-Natal holiday village Feb 10: Agreed to be extradited to US to clear his name Feb 14: US authorities discover Mr Bond is claiming mistaken identity Feb 25: US prosecutor tipped off about "real" Mr Sykes in Las Vegas Feb 26: Mr Bond released Click here for how the mix-up happened

He said: "I'm thrilled for him, but he does look very tired - he doesn't look as well and as fit as he did before he left.

"He has obviously gone through a most harrowing ordeal, but it is good to see him back."

Mr Bond thanked the media for drawing attention to his case, but also complained bitterly about some of the intrusive "dirty tricks" used to get access to him.

He added that he had had a personal phone call from South African president Thabo Mbeki, who had apologised to him and invited him to tea if he ever returned to South Africa.

Mr Bond's wife Audrey, who had been on holiday with him, said she now hoped they could go home and be reunited with their children in peace.

Mr Bond had been mistaken by the FBI for their real wanted man, multi-million pound fraud suspect Derek Lloyd Sykes.

Mr Sykes, also a British citizen who is now in custody and awaiting trial in Texas, may have used the name Derek Bond as long as 14 years ago.

And Mr Bond's passport number had somehow been added to the FBI "wanted" notice about Mr Sykes, the news conference heard.

It was only when the case received publicity in the US, that the FBI received a tip-off from somebody who knew Mr Sykes, that he was arrested and Mr Bond released.

Mr Sykes, who denies the charges, is accused of involvement in a 1990s scam which cost 210 people more than �3million.