Sources close to the Barack Obama's campaign for the White House indicated that former President's reluctance to reveal the names of the donors to his presidential library and "even concerns about possible extra-marital affairs" mean that his wife would not pass the vetting procedure all potential running mates have to undergo.

"It is absolutely standard operating procedure that vice-presidential candidates today must be fully vetted," a Democratic official close to the Obama campaign was quoted as saying by the The Daily Telegraph of Britain.

"That means their finances and everything about them...There's a questionnaire. It covers everything, including, 'Have you got any girlfriends?'"

A Democratic strategist aligned with the Obama campaign said before Hillary could be considered a VP candidate, the Obama campaign would have to see those records to know how the money was raised and "whether there are any ticking time bombs in there."

"The Clintons were pretty adamantly against it when her candidacy was on the line so it's hard to see how they'd be for it for Obama's candidacy," the strategist noted.

According to the report, Obama told a prominent supporter of Hillary that he viewed the former president as a "complication" that made it more difficult for him to choose the former First Lady, who has made clear she would like to be on the Democratic ticket with him.