Three top executives of the Russian space company Energia, which designs and manufactures the Soyuz and Progress spacecrafts, have been arrested for alleged fraud, investigators said on Sunday.
"Energia's deputy director Alexei Beloborodov and two of his subordinates were arrested and charged with attempted fraud," the Investigative Committee of Russia said in a statement.
The arrests come as part of a probe conducted "with the active assistance" of the main Russian intelligence agency, the FSB, the statement added.
At the end of July, the FSB carried out several searches targeting the Russian space industry as part of an investigation into "high treason", according to Russian media.
The raids were at the Central Research Institute of Machine-Building (TsNIImash), Russia's leading research institute for the space industry, and one of its employees, Viktor Kudriavtsev, was arrested.
According to the Russian daily Kommersant, a dozen Russian space industry employees are suspected of having sent classified information about Russian hypersonic weapon projects to Western security services.
Russian president Vladimir Putin in March boasted at a state-of-the-nation address of new "invincible" weapons under development, including hypersonic missiles.