Bombshell allegations in a new book say Feds dismissed claims made by ex-Chicago kingpin Rod Blagojevich about big money payoffs in cash to BARACK OBAMA in 2004.

The Chicago Tribune reported that an upcoming book about former Illinois Governor and “Celebrity Apprentice” Rod Blagojevich reveals undercover recordings made by the FBI caught Blago saying he’d had heard that convicted influence peddler Antoin "Tony" Rezko secretly channeled $25,000 in cash to Barack Obama but law enforcement didn’t find the tip credible.

According to the book, "Golden: How Rod Blagojevich Talked Himself Out of the Governor's Office and Into Prison," Blagojevich was caught on tape discussing an undisclosed payment to Obama for his 2004 run for U.S. Senate. BUT, the book says, the FBI ignored the seemingly off-hand remark made by a blustery polico.

"Never was Blagojevich seen as a credible threat to the incoming president,"  the book reveals, which was written by two Chicago Tribune reporters, The Chicago Tribune reported.

Obama campaign spokesperson Ben LaBolt  said the claim "is preposterous and it is false. No such payment was ever offered or made, and there never has been any suggestion or question of it from anyone, EXCEPT apparently by Rod Blagojevich."

The now-imprisoned Rezko’s attorney, Joseph J. Duffy, also dismissed the allegation, saying Blagojevich's claim is "simply a fabrication and not true.

"You must keep in mind that the source of this allegation is inherently unreliable and not credible," said the attorney.

During the 2008 Presidential campaign, Obama's ties to Rezko were one of several issues raised. Rezko and Obama had been friends, and Rezko raised as much as $250,000 for Obama for the first three political offices he sought.

Obama later acknowledged a lapse in judgment over his involvement with Rezko.

Blagojevich's claims about the cash pay off to Obama were captured on a government recording that was not made public during Blagojevich's trials. The book’s authors have not divulged how they acquired the government recordings. “Deep Throat”, perhaps?

Politics in Chicagoland has always been a dirty business  — since the mob rule of Al Capone to ex-bootlegger Joseph Kennedy buying the Presidency for JFK to the corruption of a Blagojevich – it’s nothing new.

BUT political insiders are calling the timing of the publication of this book part of an ongoing “smear campaign” in a very nasty game of one-upmanship between the Presidential combatants.