Stephen Hawking's decision to boycott an Israeli conference in protest at the state's 46-year occupation of Palestine was derided as hypocritical by some, who pointed out that the celebrated scientist and author uses Israeli technology in the computer equipment that allows him to function.

Hawking, 71, has suffered from motor neurone disease for the past 50 years, and relies on a computer-based system to communicate.

According to Shurat HaDin, an Israel law centre which represents victims of terrorism, the equipment has been provided by the hi-tech firm, Intel, since 1997.

"Hawking's decision to join the boycott of Israel is quite hypocritical for an individual who prides himself on his whole intellectual accomplishment. His whole computer-based communications system runs on a chip designed by Israel's Intel team. I suggest if he truly wants to pull out of Israel he should also pull out his Intel Core i7 from his tablet," said Nitsana Darshan-Leitner of Shurat HaDin.

Intel could not be reached for comment, but their website quotes Justin Rattner, chief technology officer, as saying earlier this year: "We have a long-standing relationship with Professor Hawking." He added: "We are very pleased to continue to … work closely with Professor Hawking on improving his personal communication system."

Cambridge University declined to comment on allegations of hypocrisy regarding Hawking's communications system.

• This article was amended on 9 May 2013 to remove a reference to Intel being an Israeli firm. It is a US multinational with bases in Israel.