Last April, Vladimir Putin visited the campus of Bauman Moscow state technical university, set on the banks of the Yauza River in the east of the city and home to some of the country’s brightest scientific minds.

He toured the campus, met undergraduates and boasted about Moscow’s ambitious plans for space missions to the moon and Mars. “You have everything it takes to be competitive,” Putin told the students.

What the Kremlin readout of Putin’s visit did not mention was a secret faculty inside the university, known simply as Department 4, or “Special Training”.