updated 8:51 p.m. ET April 28, 2006

NEW YORK - The NFL players union is investigating the role of agent David Caravantes in rent payments made for the family of Heisman Trophy winner Reggie Bush.

The NFL, meanwhile, has alerted some teams about a potential extortion of Bush’s family after the Southern Cal running back didn’t sign with a marketing company tied to Caravantes.

Gene Upshaw, executive director of the NFLPA, confirmed Friday that the investigation of Caravantes has begun.

“I can’t comment on specifics of the investigation while it is going on, according to our organization’s regulations,” he said. “Until the process is completed, we can’t comment, other than the investigation is ongoing.

“Things like this are about the integrity of the game and our sport, and we have to make sure it is dealt with sufficiently.”

Caravantes told The Associated Press on Friday “I have not heard anything” about the NFLPA investigation. He also said: “I have had no involvement with Reggie Bush. The truth will come out.”

The league’s security department contacted several teams about the situation. Houston Texans owner Bob McNair, whose team has the first overall selection in Saturday’s draft and has said it will pick either Bush or North Carolina State defensive end Mario Williams, said Thursday he was aware of the situation.

According to newspaper reports, Bush’s parents didn’t pay $54,000 in rent during the year they lived in the house owned by a sports marketing agency investor who wanted to represent the football star.

The landlord, Michael Michaels, said that Bush’s mother and stepfather agreed to pay $4,500 in monthly rent when they moved into the Spring Valley house he bought for $757,000 in March 2005, the San Diego Union-Tribune reported Friday.

They didn’t pay for the first few months, but promised to pay when the Heisman Trophy-winner started earning millions of dollars after turning pro, said Michaels, who described himself as a real estate investor.

FREE VIDEO Getting ready for draft day April 27: Former USC stars Reggie Bush and Matt Leinart discuss the upcoming NFL draft. NBC Sports

Michaels’ attorney, Brian Watkins, claimed Bush was made aware of the situation and also promised to repay the debt when he turned professional, according to a report in Friday’s Los Angeles Times.

“Originally there was a rental agreement, but they never paid a dime,” Watkins told the Times. “It was always, ‘Don’t worry, we’ll pay you — you can take it out of our profits.”’

Bush, however, did not sign with Michaels’ firm, New Era Sports & Entertainment LLC — to which Caravantes also has been linked. Watkins said the running back’s stepfather helped found the company.

Slide show   Mr. President Images of Heisman winner Reggie Bush's stellar season for USC

About the $54,000 Michaels claims he’s owed by the Bush family, Caravantes said: “I wasn’t even aware of the money asked of the Bush family until yesterday.”

Watkins sent the player’s parents an eviction notice on April 3, a copy of which he showed the Union-Tribune.

Bush’s parents, LaMar and Denise Griffin, moved out of the house last week. Bush has said his parents left because they found another place to live.

Watkins said he plans to file a $3.2 million fraud lawsuit against Bush’s parents and possibly Bush. The sum includes $300,000 in money that Michaels claims he and another investor, a documented gang member named Lloyd Lake, put into the business, plus punitive damages.

Watkins and David Cornwell, the Bush family attorney, did not immediately return phone calls from The Associated Press late Thursday.

According to ESPN, Caravantes threatened to reveal embarrassing personal information about the Bush family if he did not receive the money and tried to evict the family from a San Diego house they rented from his business associate Michael Michaels.

NFL DRAFT Draft HQ: Round-by-round, pick-by-pick recap   Video: top storylines from draft Borges: Jets get top grade; Bears, Bills blow it Opinion: Broncos put Plummer in tough spot USC's Leinart, Bush, White all fall in draft Second day for converted quarterbacks Notebook: Bloom hopes to blossom Texans happy to draft 'special' player Saints swoop quickly to nab Bush at No. 2 Titans thrilled to take Young | End White's slide Fans cheer when Jets pick Ferguson at No. 4 Leinart has 'no regrets' | Fall to hurt colleges Vote: Who had best, worst drafts? Vote: Which QB will start first?

Watkins and David Cornwell, the Bush family attorney, did not immediately return phone calls from The Associated Press late Thursday. Caravantes has not returned repeated phone messages from the AP.

NFL spokesman Greg Aiello said in a statement Friday, “Based on the information presented by Reggie Bush’s attorney, our office has advised the attorney to consider referring these matters to law enforcement authorities.”

Bush has denied knowledge of any deal with Michaels and has promised that details would emerge later that would explain the family’s living situation.

“I’m confident and I know what the truth is,” he said Thursday at a pre-NFL draft appearance in New York. “I know for a fact that everything is fine and this is all blown out of proportion and there’s more to the story than is being told right now.”

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