A scientist at one of Russia’s leading space research labs has been charged with state treason after a suspected leak of hypersonic missile secrets to the West.

Central Research Institute of Machine Building (TsNIImash) employee Viktor Kudryavtsev, 74, was arrested last week after security services raided two research facilities linked to the federal space agency, Roscosmos. Roscosmos said this week the suspected leak took place in 2013, while Kudryavtsev’s son said authorities had first conducted searches and seized documents at his home in September 2017.

“Our defendant Kudryavtsev was formally charged with state treason today,” attorney Ivan Pavlov was quoted as saying by the state-run TASS news agency on Thursday.