Prez Mahama says he has never accepted a bribe. Do you believe that?

President John Dramani Mahama boldly says that he has never accepted a bribe. The President took part in London's Anti-Corruption Summit which was organized by the UK Government, said this in response to a direct question posed by a BBC Journalist.
In an interview with the BBC on the sidelines of the summit, President Mahama said, “Any human being would have encountered corruption in one way or the other. What you need to do is to put yourself in a position to (resist it)”, the President said.

But when was specifically asked if he had ever taken a bribe before, the President was quick to say no, “I haven’t taken a bribe.”

Before leaving for the summit, President Mahama said, “the London Summit provides an opportunity to demonstrate once again the measures we have been adopting to strengthen our fight against corruption, combat money laundering and counter the financing of terrorism.”