Who are the three Russian hypersonic missile scientists accused of state treason?

Colleagues of Anatoly Maslov, Alexandr Shiplyuk and Valery Zvegintsev say their prosecution would damage Russian science. (Supplied: ITAM)

Three Russian scientists who have worked on hypersonic missile technology face "very serious accusations" of state treason, the Kremlin says.

Colleagues of Anatoly Maslov, Alexandr Shiplyuk and Valery Zvegintsev this week published an open letter in their defence, warning that prosecuting them threatened to damage Russian science.