Ukraine’s security agency says it had detained a government official accused of spying for Russia.

The security service, or SBU, said the suspect, named in reports as Stanislav Yezhov, an aide to Prime Minister Volodymyr Groysman, allegedly passed government secrets to his Russian handlers.

Ukraine’s security service said Mr Yezhov acted “on the orders” of Russia to collect information “about the activities of government structures”, with the help of “special equipment”. The official gave data to the Russians through “electronic channels of communication”. Mr Yezhov’s home and workplace are now being searched by Ukrainian security services, they indicated.

British prime minister Theresa May said on a trip to Warsaw that she was aware of reports that an interpreter for Ukraine’s premier who was photographed with her in Downing Street had been arrested on suspicion of being a Russian spy. Mrs May’s spokesman told a Westminster briefing: “Security at Downing Street is kept permanently under review.”

Russia and Ukraine have been in a tug-of-war following Moscow’s 2014 annexation of Crimea and support for pro-Russia insurgency in eastern Ukraine. -(PA)