British police have been involved in the case of a British embassy employee arrested in Germany on suspicion of spying for Russia for “a number of months”, the head of Scotland Yard said. David Smith, a 57-year-old British national, was detained on Tuesday after a joint investigation by British and German authorities. He is understood not to be a diplomat but a private contractor working as a security guard at the Berlin embassy so does not hold diplomatic immunity. The German federal prosecutor’s office said the man was suspected of selling documents obtained during the course of his work to “a representative of a Russian intelligence service”. Asked about Metropolitan police involvement in the case, Dame Cressida Dick, the Met police commissioner, told LBC radio: “We have been involved for a number of months in the Met. It’s a very good example of international co-working. We’ve been working closely, of course, with the German authorities, the BKA [German federal police], and the prosecutors, and of course with the UK government. “Somebody has been arrested, suspected of involvement in what they call intelligence agent activity. We will continue to work closely with them and through the next steps. If this person is charged we will support any trial, wherever that may be. At the moment the Germans are most certainly handling it.” The incident has prompted calls for a security review of UK embassy contractors. The Conservative MP Tobias Ellwood, chair of the Commons defence select committee, called on the government to review the security of all contractors working at UK embassies, which he described as “standard protocol following such an incident”, adding that this incident was a “disturbing throwback to the cold war days”. But the former national security adviser Peter Ricketts said the UK should not overreact, after calls for a review of embassy security contractors in light of the arrest in Berlin. Lord Ricketts, who was security adviser to David Cameron, told BBC Radio 4’s Today programme: “It tells me that we’re probably not looking at highly classified information being passed to the Russians – a security guard would not have access to that.” However, Ricketts said the case served as a reminder that the Russians continued to deploy traditional espionage methods to prise secrets from their rivals. “We all think now about the Russians stealing secrets by hacking and providing disinformation by social media and so on. It is a reminder that the Russians haven’t given up on the old-fashioned ways of suborning individuals through money. I think the Russian intelligence threat to all our countries has grown again.” The suspect is alleged to have worked for a Russian intelligence agency at least since November 2020, and is suspected of at least once passing on documents he had acquired through his work to a handler. He is alleged to have been paid a cash bribe to pass information to Russian intelligence. Citing prosecutors’ circles, the German news magazine Focus reported on Wednesday that the information passed on related to counter-terrorism issues. The suspect was under surveillance by British and German investigators, believed to have included MI5, but officials were reluctant to discuss when that began. Smith was arrested at his Potsdam apartment at 2.20pm on Tuesday, and his home and embassy workplace were searched. A government minister said it would “not be appropriate” to comment on the arrest of a British embassy employee in Germany on suspicion of spying for Russia. The schools minister, Nick Gibb, said: “I don’t feel I am able to talk about this issue. This is now subject to a police investigation.” Pressed on why a government representative could not say more, Gibb added: “Because this is a matter for police investigation, it would not be appropriate for any minister to come on your programme and discuss this particular issue.”