BBC director general Tim Davie said: "Across the BBC, we are all incredibly sad to hear the news about George. We are thinking of his family at this time.
"George was one of the best and bravest journalists of his generation who reported fearlessly from across the world as well as presenting the news flawlessly.
"He was more than just an outstanding journalist, audiences could sense his kindness, empathy and wonderful humanity. He was loved by all and we will miss him enormously."
