THE son of union leader Jimmy Hoffa – who mysteriously vanished 50 years ago – has unveiled a new theory that could explain his disappearance.

James P Hoffa opened up about his dad’s death as he made a desperate call for President Donald Trump to release a trove of FBI files.

On July 30, 1975, embattled labor leader Jimmy disappeared on the very day he intended to meet with American mobsters Anthony Provenzano and Anthony “Tony Pal” Giacalone.

He was stood up for the meeting at a restaurant in Detroit, Michigan, so he called his wife on a payphone and told her that he was coming home.

However, he never made it back.

Jimmy’s car was abandoned outside the restaurant, and there was never any sign of him. He was pronounced legally dead in 1982.

Now, in a new interview, James has revealed what he believes happened that dark day.

In an interview with Fox Nation, James shared his belief that Giacalone might have picked Jimmy up from the restaurant and subsequently taken him to a secluded location where he was murdered.

He speculated that Giacalone enlisted the help of his other brother Anthony “Tony Pal” Giacalone to commit the sick crime.

James suspects that the mobsters were unhappy with Jimmy’s ambitions to reclaim his position as president of the International Brotherhood of Teamsters, a very influential labor union.

Jimmy had served in the position from 1957 to 1971, but his tenure was cut short when he was found to have ties with organized crime.

After serving a stint in jail, Jimmy was ready to return to IBT and rid all ties to the mob, according to James.

But this was met with resistance from crime bosses who were believed to have been making hundreds of millions from the relationship.

James said that his dad’s determination to turn his life around is what ultimately got him killed.

“They actually got together to kill him because they couldn’t stop him any other way,” he told Fox Nation.

“The only way to stop him was to kill him.”

CALLS FOR EVIDENCE

A vast collection of documents from the investigation into Jimmy’s murder has already been released, but James said this isn’t enough.

He said that many of the files were redacted to the point where he wasn’t sure what he was reading.

Now, he believes that only Trump has the power to release the unredacted files and shine new light on his father’s death.

In a final plea, James said, “Let’s find out what really happened. President Trump, release the files.

“I can’t say what is in those files. That’s exactly why they need to be released. The American public, the Teamsters union, its members, and our family have a right to know what’s inside, and I think you’ll make it happen.”

The new series Riddle: The Search for James R. Hoffa with Eric Shawn is now streaming on Fox Nation.

The son’s call for change comes after a group of sleuths said that they have a new theory on where Jimmy is buried.