British cosmologist Professor Stephen Hawking has announced his withdrawal from an Israeli conference in Jerusalem, prompting reports that he is supporting an academic boycott on the country.
Hawking was due to appear at the conference, hosted by Shimon Peres, the Israeli president, but his name was recently dropped from the list of speakers.
A statement on the website of the British Committee for the Universities of Palestine said: "We understand that Professor Stephen Hawking has declined his invitation to attend the Israeli Presidential Conference, Facing Tomorrow 2013, due to take place in Jerusalem on 18-20 June.
"This is his independent decision to respect the boycott, based upon his knowledge of Palestine, and on the unanimous advice of his own academic contacts there."
Agencies reported that the University of Cambridge, where Hawking works, confirmed the statement had been approved by the professor.
Israel Maimon, chairman of the Israeli Presidential Conference, said on Wednesday that Hawking's decision was "outrageous and wrong".
"The use of an academic boycott against Israel is outrageous and improper, particularly for those to whom the spirit of liberty is the basis of the human and academic mission," he said.
"Israel is a democracy in which everyone can express their opinion, whatever it may be. A boycott decision is incompatible with open democratic discourse."
Not for 'Health reasons'
The University of Cambridge initially cited health reasons for the change of plans.
"For health reasons, his doctors said he should not be flying at the moment so he's decided not to attend," university spokesman Tim Holt said in a statement earlier on Wednesday
University officials later said that they had "previously understood'' that Hawking's decision was based solely on health concerns - he is 71 and has severe disabilities - but had now been told otherwise by Hawking's office.
Hawking's decision means that one of the world's most famous scientists has joined a boycott organized to protest Israel's treatment of Palestinians.
The presidential conference traditionally draws hundreds of leading world figures, including Tony Blair in 2011 and George W Bush in the inaugural conference in 2008.
Numerous figures from the world of art and entertainment have also refused to perform in Israel in recent years as part of an effort to promote the Palestinian cause, including musicians Elvis Costello and Stevie Wonder, and actors Dustin Hoffman and Meg Ryan.
Israel has also been boycotted by athletes, with basketball star Karem Abdul-Jabbar cancelling a trip in 2012 and Tunisian fencing champion Sara Besbes refusing to take part in a competition in Italy rather than face an Israeli fencer.