International's British branch chief, Keith Allen, said Microsoft helped Israeli Police interrogate Mordechai Vanunu, who leaked nuclear secrets to the foreign press.
Allen, writing in the British Sunday newspaper, the Observer, wrote: "Amnesty is concerned about its co-operation with the Israeli authorities in prosecuting nuclear whistleblower Mordechai Vanunu for communicating with foreign journalists. Vanunu was imprisoned for more than 18 years after disclosing Israel's nuclear capabilities to the UK media, and only released on condition he stays in Israel and does not talk to foreigners. Microsoft is reported to have complied with government demands for his computer records, which could lead to him being sent back to prison."
Amnesty International did not give further details about its claims. The organization's website claimed that the judge in Vanunu's case agreed not to base his decision on information obtained by Microsoft, but added that the details in the hands of the authorities could limit Vanunu's freedom in the future.
Readers of the site were asked to send a formulated petition on what Amnesty International called Microsoft's "repression of human rights" in Israel and other countries.