Russia's sacked transport minister has been found dead in his car outside Moscow with a gunshot wound and the principal hypothesis is that he took his own life, state investigators said on Monday, hours after President Vladimir Putin fired him.

A presidential decree published earlier on Monday gave no reason for the dismissal of Roman Starovoit, 53, after barely a year in the job, though political analysts were quick to raise the possibility that he may have been dismissed in connection with an investigation into corruption in the region he once ran.

These suggestions could not be independently confirmed, though a transport industry source, who declined to be named due to the sensitivity of the matter, said Starovoit's position had been in question for months due to questions about the same corruption scandal.