A 32-year-old man has lost more than £130,000 in an internet scam involving Nigerian fraudsters.
Police said the victim, from Portsmouth, was befriended online by a man posing as a woman in 2007.
He was asked for money to help the "woman's" dying mother and believed he also funded the funeral.
He then got emails from people posing as FBI agents investigating the scam, who duped him into funding trips to Nigeria so they could investigate.
The money cannot be recovered due to the current political situation in Nigeria
Det Con Jon Knox
A Hampshire police spokeswoman said: "It eventually transpired that the woman was in fact a Nigerian man who had been lying to obtain money from the man in Portsmouth."
The spokeswoman said the victim later received further emails from someone else purporting to be another victim of the fraud as well as men who claimed to be FBI agents.
"The agents said they would take on the Portsmouth man's case if he would fund their trip to Nigeria and any subsequent costs they incurred, which the man agreed to," she said.
"This went on for many months before it again transpired that the emails were fraudulent, and in fact another attempt to obtain money from the man.
"The money cannot be recovered due to the current political situation in Nigeria, resulting in a lack of co-operation from the police in the country."
Det Con Jon Knox said: "This is a very sad situation, and this man has now parted with a huge sums of money through his own good nature - in trying to help others and then to recover some of what he had lost.
"We do not want anyone else to fall foul of this kind of shocking activity and I would warn anyone who is asked for money over the internet by people they do not know to refuse and not put yourself at risk."