The homeless man who gave his last $20 to help a stranded Philadelphia motorist says he has been locked out of hundreds of thousands of dollars raised for him through a viral GoFundMe campaign.

And now he’s back living under a bridge, addicted and panhandling for change.

GoFundMe is investigating the hero hobo’s claim that the woman he helped and her live-in boyfriend may have set up the online fundraiser only to steal the donations.

Some $400,000 was raised on GoFundMe for Johnny Bobbitt, 35, after he helped Kate McClure when she ran out of gas in a dicey Philly neighborhood this past November.

More than 14,000 people made donations after the story was featured on ABC’s “Good Morning America,” the BBC and other media.

“He will never have to worry about a roof over his head again!!” the couple had promised on GoFundMe.

But now the good deed heard round the world has devolved into a bitter public battle.

McClure, 28, and boyfriend Mark D’Amico, 39, both of Florence Township, NJ, insist they’ve spent half the fundraiser money on housing and other expenses for Bobbitt. They say they are holding the rest until he’s off drugs.

Bobbit once blew through $25,000 cash in under two weeks, they claimed to the Philadelphia Inquirer.

“Giving him all that money, it’s never going to happen. I’ll burn it in front of him,” D’Amico told the newspaper.

With Bobbitt’s opioid addiction, handing him another chunk of money would be like “giving him a loaded gun,” he said.

But Bobbitt wonders why the couple has been posting to Facebook and Instagram photos of pricey-looking vacations to California, Las Vegas and the Grand Canyon.

McClure, who is also the owner of a new BMW, is a receptionist for the New Jersey Department of Transportation. D’Amico is a carpenter.

“I think it might have been good intentions in the beginning, but with that amount of money, I think it became greed,” Bobbitt told the Inquirer.

The North Carolina native spoke as he sat under a bridge with his homeless brother, Josh, 34, and a sign reading, “Homeless Hungry Anything Helps Thank You! God Bless!”

Johnny Bobbit said they had been living there since June, when he was kicked out of a camper the couple bought him and set up in their yard.

McClure declined to speak to The Post on Friday.

But a next-door neighbor remembered Bobbitt as an aggressive presence who constantly demanded money.

“I just gave you money!” he recalled hearing D’Amico shout.

A GoFundMe representative said in a statement that the company was investigating both sides’ allegations.

Additional reporting by ­Richard Harbus