A British embassy employee in Berlin has been arrested on suspicion of spying for Russia, German prosecutors have said.
The 57-year-old British national – identified by authorities only as David S but named in reports as David Smith – was detained on Tuesday following a joint investigation by British and German authorities.
The German Federal Prosecutor’s Office said the man is suspected of selling documents obtained during the course of his work to “a representative of a Russian intelligence service”.
He appeared before an investigating judge at the Federal Court of Justice in Karlsruhe on Wednesday where he was ordered to remain under arrest pending further inquiries.
British officials would not comment on reports that the suspect was working as a security guard at the embassy.
The Metropolitan Police said officers from the force’s Counter Terrorism Command – which investigates alleged breaches of the Official Secrets Act – are liaising with their German counterparts who have “primacy” for the investigation.
The PA news agency understands, however, that the British security services have considerable involvement in what is being described as an intelligence-led operation.
The man – who was arrested in the city of Potsdam, to the south-west of Berlin – is being held under German law on suspicion of engaging in “intelligence agent activity”.
Following his detention, searches were carried out at his home and at his workplace.
The German Foreign Ministry said it is taking the case “very seriously”.
Foreign minister Heiko Maas told reporters: “Spying on a close ally on German soil is absolutely unacceptable and we are in full solidarity with our British friends.
“We will be following the federal prosecutors’ further investigations very closely. And where that’s desired, necessary and possible, we will also support them.”
For Labour, shadow home secretary Nick Thomas-Symonds said the case represented a “serious breach” of UK national security.
“All measures must now be taken – urgently – to establish exactly what information has been passed to Russian intelligence and the impact this has on the UK, as well as that of our allies,” he said.
A UK Government spokesman said the suspect had been “contracted to work for the Government”, while German prosecutors said he had been working as a “local employee” at the embassy.
In a statement, the German Federal Prosecutor’s Office said he is suspected of having worked for a foreign secret service since at least November last year.
“On at least one occasion he forwarded documents obtained in the course of his professional activities to a representative of a Russian intelligence service,” the statement said.
“In return for providing information, the accused received cash in a previously unknown amount.”
Tom Tugendhat, the Conservative chair of the Commons Foreign Affairs Committee, said reports suggesting the detainee was a contracted security guard meant he was likely to be “relatively low down” in rank.
The former minister told BBC Radio 4’s PM programme: “We are not talking about some sort of Kim Philby-type story.
“We are talking about somebody relatively low down on the rank of the ladder who has clearly made some very unwise decisions and has possibly even betrayed their country and is now, we don’t know, but he may be a traitor.”
In a statement, the Metropolitan Police said: “The man was arrested in the Berlin area on suspicion of committing offences relating to being engaged in ‘intelligence agent activity’ (under German law).
“Primacy for the investigation remains with German authorities. Officers from the Counter Terrorism Command continue to liaise with German counterparts as the investigation continues.”
A UK Government spokesman said: “An individual who was contracted to work for the Government was arrested yesterday by the German authorities.
“It would not be appropriate to comment further as there is an ongoing police investigation.”
The arrest comes at a time of continuing tensions between the UK and Russia, which have been building for a number of years.
In June, a Royal Navy warship was buzzed by Russian fighter jets when it sailed through disputed waters off Crimea which was annexed by Moscow from Ukraine.
In 2018, Britain expelled 23 Russian intelligence officers following the poisoning attack on former spy Sergei Skripal in Salisbury, which persuaded allies to eject dozens of others.