Sky News briefly reported that Megrahi had died just after 4pm today.
But Megrahi's lawyer, Tony Kelly, told Reuters: "It's absolutely untrue. He's definitely not dead."
"I'm not saying anything about his health condition other than the fact he is alive and breathing," Kelly said.
Megrahi, who was suffering from terminal cancer, was released from a Scottish prison by Justice Secretary Kenny MacAskill earlier this year on compassionate grounds.
He was convicted of mass murder for the bombing of Pan Am Flight 103 over Lockerbie on 21 December 1988.