Professor Richard Dawkins sparked a Twitter backlash by claiming Muslims have been awarded fewer Nobel Prizes than Trinity College, Cambridge, adding: "They did great things in the Middle Ages, though".
An online row broke out when he posted: "All the world's Muslims have fewer Nobel Prizes than Trinity College, Cambridge."
The outspoken author went on to defend the remarks which sparked fury on the social network where he was accused of disguising his "bigotry" as atheism.
A series of high-profile Twitter users condemned his comments, prompting Prof Dawkins to question what Muslims had achieved since the Dark Ages.
He responded to the barrage of ensuing criticism by telling his followers: "A statement of simple fact is not bigotry. And science by Muslims was great in the distant past."
In a further posting he wrote: "Where would we be without alchemy? Dark Age achievements undoubted. But since then?"
He sought to justify the observation by adding: "Why mention Muslim Nobels rather than any other group? Because we so often hear boasts about (a) their total numbers and (b) their science."
One angry Twitter user hit out at the remarks telling the author: "You absolutely disgust me."
Writer Caitlin Moran added: "Think it's time someone turned Richard Dawkins off and then on again", while Channel 4 News Economics Editor Faisal Islam questioned Prof Dawkins' "spurious use of data".
Writer and Independent columnist Owen Jones responded: "How dare you dress your bigotry up as atheism. You are now beyond an embarrassment."
The author of The God Delusion - who branded religion a "betrayal of the intellect" and "a betrayal of all that's best about what makes us human" - found himself at the centre of controversy earlier this year when he challenged the Archbishop of Canterbury at the Cambridge Union debate, saying: "If I were a cultural Muslim, I would have something to say about that faith's appalling attitude to women and various other moral points."
Dawkins has since removed the tweets from his page.