Russia's Federal Security Service (FSB) has raided a space research facility after a suspected leak of hypersonic missile secrets to Western spies.
The state space agency Roskosmos said its security staff were co-operating with FSB officers on a criminal case.
Russia's Kommersant daily says about 10 staff at a Roskosmos facility called TsNIIMash are under suspicion. A director's office was searched.
On Thursday Russia released video of new hypersonic missile systems.
"It was established that the leak came from a TsNIIMash employee," a source told Kommersant.
TsNIIMash is a top scientific subsidiary of Roskosmos, which runs Russian space programmes.
Russia's defence ministry has broadcast video of what it calls a new generation of hypersonic missiles, which can carry nuclear warheads. Some are launched by bombers, others are shown being launched from silos or mobile launch vehicles.
President Vladimir Putin spoke about the systems in March, including the Kinzhal missile which can reach Mach 10 - about 12,000km/h (7,456mph), with a range of 2,000km.