The exact illness leading to the hospitalisation of the 87-year-old Sinha, who had quit Army in 1983 after he was superseded for the post of Army Chief, is not clear, they said.
Noted for his grasp of military knowledge and strategies, his tenure as Assam Governor had been recognised for his contribution to the turn-around in the insurgence-hit state's internal situation in late 90s.
An author of several books, he was also ambassador to Nepal.