SAN DIEGO -- The existence of taped conversations between Reggie Bush or members of his family and an investor in a failed sports marketing agency could confirm the New Orleans Saints running back received cash and gifts while playing for Southern California, Yahoo.com reported Wednesday.

A federal investigation into extortion claims by Bush and his family revealed the existence of the taped conversations, according to the Yahoo.com report.

The U.S. Attorney's office in San Diego has issued grand jury subpoenas to multiple witnesses in the probe, Yahoo.com reported. According to a copy of a subpoena obtained by Yahoo, at least one of the witnesses was asked to hand over "any recordings in your possession of conversations between Lloyd Lake and Reggie Bush, Denise Griffin or LaMar Griffin."

Lake, who founded a sports marketing agency in hopes of landing Bush as its first client, is the subject of a grand jury probe into the extortion claims. Denise Griffin is Bush's mother, and LaMar Griffin is Bush's stepfather.

Yahoo.com, citing unidentified sources, reported LaMar Griffin spoke with federal investigators in the spring of 2006 and acknowledged the existence of the tapes.

"We're aware of an investigation into possible criminal conduct by Lake and others associated with him," Bush attorney David Cornwell told ESPN's Joe Schad on Wednesday. "We have and will continue to cooperate with the Department of Justice."

When asked in the past about the allegations of receiving inappropriate extra benefits, Bush has insisted that he and his family did nothing wrong.

Multiple sources told Yahoo.com that Lake made the tapes in late 2005 to protect his financial investment if Bush backed out of a deal to sign with New Era Sports & Entertainment, founded by Lake and San Diego businessman Michael Michaels. In January 2006, Bush signed with agent Joel Segal and marketing agent Mike Ornstein.

On Jan. 12, 2007, Lake's mother, Barbara Gunner, testified before a grand jury, according to the Yahoo.com report, that she had heard portions of tapes made by her son, in which LaMar Griffin states Bush intended to repay New Era Sports "their money," as well as for a car purchased for him.

"I respectfully decline to comment on the media frenzy regarding Reggie Bush, his family and his college career," Cornwell told Yahoo on Wednesday.

Lake told Yahoo in August 2006 that he contributed a portion of the cash and gifts allegedly given to Bush and his family as part of an agreement to represent the 2005 Heisman Trophy winner when he signed an NFL contract. In September, Yahoo.com reported Ornstein also supplied Bush and his family with gifts while he was still at USC.

According to Yahoo.com, nearly $280,000 in cash, rent and gifts was allegedly given to Bush and his family.

The Pac-10 Conference and the NCAA are investigating whether Bush or his family broke NCAA rules and compromised his eligibility during the 2004 and '05 seasons by taking extra benefits.

If Bush is found to have violated NCAA rules, USC, which won a national title in '04 and played for the '05 championship, could be sanctioned.

Also, the Heisman Trophy Trust requires players be in good standing with the NCAA to be eligible for the award given to college football's top player. If Bush is ruled ineligible by the NCAA, he could be in danger of having his Heisman taken away.

LOS ANGELES - A sports marketer will hand over financial records and other evidence to NCAA investigators that would link Reggie Bush and his family to nearly US$280,000 in benefits, while he was enrolled at the University of Southern California, according to a report Wednesday.

Lloyd Lake, who allegedly provided improper benefits to Bush in 2005, has agreed to meet with NCAA officials and give them evidence to help their investigation, Yahoo! Sports reported on its website, citing two unidentified sources.

Yahoo! Sports also reported it had acquired confidential e-mails from officers of New Era Sports & Entertainment, a marketing agency founded by Lake and Michael Michaels with co-operation from Bush and his stepfather, LaMar Griffin. The e-mails show the agency soliciting marketing and memorabilia deals on the running back's behalf, Yahoo! Sports reported.

Both Yahoo! Sports and the Los Angeles Times reported Tuesday that Lake is expected to file a civil lawsuit in San Diego against Bush later this month, seeking to recoup money allegedly given to Bush and his family.

Lake's attorney, Brian Watkins, told The Associated Press on Tuesday he couldn't confirm or deny the reports. A phone message left for him Wednesday was not immediately returned.

Lake and Michaels claimed more than a year ago that they provided money to Bush's family as well as a home for which the family had failed to pay more than $50,000 in rent. The conflict was made public after Bush signed with another sports agent.

Bush, the Heisman Trophy winner as a junior in 2005, is in his second year with the New Orleans Saints, having signed a contract reportedly worth up to $60 million. He has said repeatedly that neither he nor his family did anything wrong in dealings with Michaels and Lake.

A phone message left for Bush's attorney, David Cornwell, on Wednesday also wasn't immediately returned.

Michaels reached a settlement with Bush and his family last April. Yahoo! Sports said the settlement was for between $200,000 and $300,000.

If Bush is found to have received improper benefits, USC could be forced to forfeit games. The school could face other sanctions if it's proven that coaches knew or should have known about the alleged benefits.

Also, if Bush is found to have broken NCAA rules during his Heisman-winning season, the award could be revoked.