Senator Barack Obama is a rising star of US politics

An advertisement for a feature about the whereabouts of the al-Qaeda leader carried the caption "Where's Obama?" over images of Bin Laden.

CNN has apologised for "a very bad typographical error".

A spokesman for Mr Obama, a potential presidential hopeful, said he accepted that it was an innocent error.

"Though I'd note that the 's' and 'b' keys aren't all that close to each other, I assume it was just an unfortunate mistake," his spokesman Tommy Vietor said.

The error happened on Monday night during presenter Wolf Blitzer's news programme The Situation Room.

Mr Blitzer apologised on air for the slip. "I'm going to be making a call to him later this morning to offer my personal apology," he said.

Mr Obama, tipped by some to become the country's first black president, admitted in October that he was considering a White House run in 2008.

He has always been ready to deal with questions about his unusual name.

"When I first started to work in public life... people would ask: 'Hey brother, what's with your name? You called Alabama or Yo' Mama?'"

He has also acknowledged that his full name, Barack Hussein Obama, is not ideal for someone involved in politics.