An aide to Ukraine's prime minister has been detained on suspicions he spied for Russia, Ukrainian security services announced Thursday.

Interpreter Stanislav Yezhov, 39, was apprehended Wednesday for allegedly partaking in a "long-time foreign mission" to gather intelligence from the former Soviet nation's top cabinet. In a Facebook post, Ukrainian Prime Minister Volodymyr Groysman said Yezhov had "long been working in the interests of a hostile government."

"[T]he official on the orders of the Russian curators collected with the help of special equipment information about the activities of government structures," the security services statement said. "The received data was given by the attacker to the curators through the electronic channels of communication."

Yezhov was present for meetings with U.K. Prime Minister Theresa May in July as well as with then-Vice President Joe Biden in June 2016.

It is unclear how long Yezhov might have acted as a spy for the Russian federation, but Ukrainian officials indicated that they were conducting ongoing searches at his home and workplace for more information. He is likely to face charges of state treason, according to the agency.

The discovery of an alleged Russian spy at the highest levels of the Ukrainian government comes amid ongoing hostility between Kiev and Moscow more than three years after Russian President Vladimir Putin seized Crimea and armed pro-Russia rebels in eastern Ukraine. The enmity shut down collaborations between Ukrainian and Russian intelligence agencies that formerly worked closely together.