Broadcaster and writer Stephen Fry has said he is "switching off his connections with the outside world" to concentrate on his autobiography.

The QI host, who is one of the most popular celebrities on Twitter, said he had to deliver the second volume of his life story to publishers by April.

"Some people can write with ease in whatever circumstances they find themselves," he wrote on his website.

"I need peace, absolute peace and zero distraction. I shall be as one wiped from the map of human existence.

"All this is a way of saying, of course, that my Twitter stream will dry up for that period."