Based largely on interviews with Lloyd Lake, who tried to secure Bush as a client for the marketing company he attempted to launch, "Tarnished Heisman" claims the 2005 Heisman Trophy winner was provided with hotel stays, cash for shopping sprees and money to buy and customize a car.
The book's authors, Don Yaeger and Jim Henry, acknowledge that Lake "has been compensated in return for his full cooperation," according to a story posted on the Los Angeles Times' Web site Thursday. Lake's family members also were quoted extensively.
The book hints that USC coaches may have known about some of the arrangements, but it does not provide evidence that any school official was aware of alleged improper gifts.
Bush has repeatedly denied any wrongdoing.
The NCAA and Pac-10 are investigating whether Bush and his parents took improper benefits during 2004 and 2005, when Bush was still playing college football.
If the NCAA determines that USC violated rules, the football program could have to forfeit victories from those seasons -- when the Trojans won a national championship and lost in the BCS title game against Texas -- and face additional penalties.
If Bush is found retroactively ineligible, he could lose his Heisman.
The book also contains transcripts of secretly recorded conversations that Lake claimed to have had separately with Bush and his stepfather, LaMar Griffin.
Lake and his former business partner Michael Michaels entered into an agreement with Bush and his stepfather to launch a marketing company with Bush as its main client.
The deal fell apart when Bush signed with established sports marketer Mike Ornstein.
Michaels reached an out-of-court settlement with Bush and has declined to comment. Lake is suing Bush to recoup $291,600 in cash and gifts that Bush and his parents allegedly accepted during Bush's sophomore and junior seasons.