Outspoken academic and writer Richard Dawkins has pulled out of a tour of Australia and New Zealand after suffering a minor stroke.
The 74-year-old was taken ill on Saturday but is expected to make a full recovery, according to a statement on the Sydney Opera House website.
The biologist and noted secularist author of The God Delusion had been due to appear at the landmark venue on February 28.
The statement said: "On Saturday night Richard suffered a minor stroke, however he is expected in time to make a full or near full recovery. He is already at home recuperating.
"This unfortunately means Richard will be unable to make his planned Australian and New Zealand tour.
"He is very disappointed that he is unable to do so but looks forward to renewing his plans in the not too distant future."