A former aide to the British prime minister has admitted that the country's secret service, MI6, spied inside Russia using a transmitter disguised as a rock.

The UK denied the claim when Russia released footage in 2006 purporting to show a man picking up the secret transmitter, but Jonathan Powell, who worked in Downing Street under Tony Blair, has now confirmed the story, saying: "The Russians had us bang to rights."

The new revelation may not affect diplomatic ties between the two countries, but it is sure to be an embarrassment for London.

Al Jazeera’s Neave Barker reports from Moscow.