The report said that there is "no indication of inappropriate discussions with the governor or anyone from his office about a 'deal' or a quid pro quo arrangement in which he would receive a personal benefit in return for any specific appointment to fill the vacancy."

It noted that Obama himself had no "contact or communication with Blagojevich or members of his staff about the Senate seat."

FBI agents arrested Blagojevich on December 9 after federal prosecutors alleged, among other things, that he had tried to "sell" Obama's former US Senate seat.

It is the sole authority of the Illinois governor to name a successor who would serve the remaining two years of Obama's term.

Vice President-elect Joe Biden also defended Obama team's role in the case earlier in the day.

"It's been clear that the president-elect has had no contact with Blagojevich ... or anyone on Blagojevich's team -- that he's asserted. And you'll soon find in the reports that ... there has been no inappropriate contact by any member of the Obama staff or the transition team with Blagojevich."

The report assumes significance because it has clarified lingering questions about what role, if any, top Obama aides such as his White House Chief of State Rahm Emanuel played in the scandal engulfing the governor of Obama's home state.

Critics, however, undoubtedly will then wonder why the Obama team waited until the Christmas week to release the report, as if they had wanted to bury bad news.

Obama has urged Blagojevich, a fellow Democrat, to resign, but the latter has vowed to stay on and denied any wrongdoing.