Russian police are investigating allegations that factory bosses manufacturing engines for Russia's Proton-M rocket may have swapped precious metals for cheaper alternatives.
Authorities received information which claimed that cheaper, less heat-resistant metals had been used in some second and third-stage engines engines assembled at the Voronezh Mechanical Plant, an unnamed source told the Interfax news agency.
The source also suggested that authorities could try and link failings at the factory and the crash of the Progress spacecraft last year.
"This company also assembles engines for boosters such as those used on the Soyuz rocket: like the one which failed to get a Progress MS-04 spacecraft into orbit last December," the source said.
Russia's Kommersant newspaper reported on Wednesday that Russian state space agency Roscosmos was withdrawing all second and third-stage engines for the Proton-M rocket, citing "technical reasons."
The problems are expected to delay launches from the Baikonur Cosmodrome in Kazakhstan, the first of which is now slated to take place no earlier than the summer of 2017, Kommersant reported.