LONDON — The letter informing Mohamed Sakr that he had been stripped of his British citizenship arrived at his family’s house in London in September 2010. Mr. Sakr, born and raised here by British-Egyptian parents, was in Somalia at the time and was suspected by Western intelligence agencies of being a senior figure in the Shabab, a terrorist group linked to Al Qaeda.

Seventeen months later, an American drone streaked out of the sky in the Lower Shabelle region of Somalia and killed Mr. Sakr. An intelligence official quoted in news reports called him a “very senior Egyptian,” though he never held an Egyptian passport. A childhood friend of Mr. Sakr, Bilal al-Berjawi, a Lebanese-Briton also stripped of his citizenship by the British government, was killed in a drone strike a month earlier, after having escaped an attack in June 2011.

Senior American and British officials said there was no link between the British government’s decision to strip the men of their citizenship and the subsequent drone strikes against them, though they said the same intelligence may have led to both actions.

But the sequence of events effectively allowed the British authorities to sidestep questions about due process under British law, mirroring the debate in the United States over the rights of American citizens who are deemed terrorist threats. The United States and Britain have a long history of intelligence sharing and cooperation in fighting terrorist threats.