When a homeless man in Philadelphia gave a stranded couple his last $US20 so they could buy petrol, they were so inspired that they started an online fundraiser to help him.

The goal on GoFundMe was set at $US10,000. But over nine months, more than 14,000 people donated more than $US400,000 to the man, Johnny Bobbitt Jr.

Less inspiring: He says he has yet to see any of the money. And he’s filing a lawsuit against the New Jersey couple, Mark D’Amico and Kate McClure.

Mr Bobbitt is still homeless and was panhandling until he checked into rehab.

“He is living off the kindness of strangers,” Jacqueline Promislo, a lawyer for Mr Bobbitt, said in an interview.

The couple told their side of the story on Monday morning on Megyn Kelly Today on NBC.

At first, Mr D’Amico and Ms McClure said, they tried to move the money to a bank account for Mr Bobbitt, but he did not have any identification.

They said they gave him $US25,000 in cash last Christmas but that Mr Bobbitt spent all the money in 13 days. They added Mr Bobbitt had used their Lyft account to order a car service to take him to locations known for selling and buying drugs.

Mr Bobbitt, Mark D’Amico and Kate McClure at a petrol station in Philadelphia in 2017. Photo: AAP

They decided to hold on to the rest for his own good, they said. “We didn’t want to give him the whole $US400,000,” Mr D’Amico said.

Instead of giving him more cash, they tried to buy things for him. They helped him buy a trailer he parked at their house.

“We took him and he picked it out,” Mr D’Amico said in the TV interview.

While that story played well on the show, Ms Promislo, who said she was representing Mr Bobbit at no charge, said he had no trailer.

“They bought it in their name and kept it in their name,” she said. “I believe they sold it.”

Mr Bobbitt believes the couple is spending the money on vacations and a new BMW. The couple said the car they bought was used.

Ms Promislo declined to say who was paying for Mr Bobbitt’s rehab and how long he had been in drug treatment.

“He wants the money put in a trust and assistance figuring out how to spend it,” Ms Promislo said.

A court would appoint a trustee, according to the filing, but she declined to say if a family member or her firm would be willing to take on that role.

She added, “The money was never given for Mark or for Kate, but they put the money in their own personal account.”

Mr D’Amico said in the TV interview: “I wanted to make sure that at the end of the day when he was ready, that there was something left for him.”

He did admit to gambling $US500 with Mr Bobbit’s permission but said that he had since repaid it.

Financial mismanagement of donations and fraud are not new problems for online crowdfunding sites.

“It happens more often than GoFundMe admits to,” said Adrienne Gonzalez, who runs GoFraudMe.com, a watchdog site.

For example, she said, there have been many cases of people raising money for cancer that they do not have, or failing to turn over donations raised for expenses like funerals.

GoFundMe will refund donations to donors if it suspects misuse or make sure the money gets to the beneficiary, a spokesman said.

As for Mr Bobbitt, Ms Promislo said, “He wants a home. He wants his money.”