McKnight signed a national letter of intent with USC on Wednesday and made comments during a news conference that seemed to suggest communications involving former Trojan Reggie Bush, who is now with the New Orleans Saints.

Former players are forbidden from telephoning prospective recruits, their relatives or guardians.

"We're aware of it, and we are looking into it," sports information director Tim Tessalone told The Associated Press late Thursday.

The university's action was first reported by the Los Angeles Times on its Web site late Thursday.

USC coach Pete Carroll denied any call took place, and McKnight's high school football coach said the recruit misspoke during the news conference. The star running back has been living with his high school coach, J.T. Curtis.

"It never happened," Carroll told the Times.

During the Wednesday news conference, McKnight said Carroll set up a conference call so he and Curtis could talk to Bush and ease concerns USC might face sanctions.

The NCAA and the Pac-10 Conference are investigating whether Bush or his family received "improper benefits" from agents while he was playing for USC.

Regarding McKnight, Mike Matthews, associate commissioner of compliance for the Pac- 10, said boosters are not supposed to be involved in the recruiting process but could not comment without knowing specifics. NCAA spokeswoman Crissy Schluep also said she could not comment without knowing more.

Curtis told the Times on Thursday that he spoke to Carroll during McKnight's recruitment, but not on a conference call with McKnight or Bush. He also said McKnight told him "Coach Carroll was talking to Reggie on the speakerphone and Joe was able to listen and hear Reggie Bush's side of the story," the newspaper reported.

After being informed of Carroll's denial Thursday night, Curtis called McKnight and later said the recruit never heard Bush on a speakerphone.

"He said when they came in his house, the discussion was brought up about probation and that's when the conversation came up that they had talked to Reggie, but Joe was not there," Curtis said. "He said, 'I was not on the speakerphone. I never called him and he never called me. I want to make it clear I never spoke to Reggie and he never spoke to me. I just messed it up. I shouldn't have said it that way (at the news conference).'"

Curtis said McKnight may have been overwhelmed by the attention and scrutiny that accompanied his announcement.