ISLAMABAD (Reuters) - Pakistan's President Asif Ali Zardari said on Monday that the whereabouts of al Qaeda leader Osama bin Laden remained a mystery and there was a suspicion that he could be dead.

Bin Laden, if he is still alive, turned 52 on March 10, but he is known to suffer from ill-health.

There have been reports that he had died of natural causes in the past, but they have never been corroborated, and security analysts believe intelligence agencies monitoring jihadi websites on the Internet would have picked up some chatter.