According to a Haryana government spokesman, Singh passed around 6 p.m. at the Medicity Medanta hospital here.
Earlier, in the day, state minister O.P. Dhankhar visited the hospital to enquire about the health of the former chief minister, and was told he was fine and had been shifted from the ICU to a general ward.
Hukum Singh was referred to the hospital here from the Post-Graduate Institute of Medical Sciences (PGIMS) at Rohtak Wednesday following a abdominal problem, a doctor said. He was admitted to PGIMS after he reported breathing problems.
A farmer, teacher, and trade unionist, he was born in Charkhi Dadri in Bhiwani district where he was elected from the local assembly constituency thrice before July 1990 when he became chief minister and ruled till March 1991 when the Janata Dal was ruling the state.
Haryana Chief Minister Manohar Lal Khattar expressed grief over Singh’s death, describing him as a seasoned politician who always worked for the uplift of the weak and downtrodden.
The state government has declared three day state mourning till Feb 28, when the flag will be flown at half mast throughout the state, and there will be no official entertainment.
The government has also declared Feb 27 as a public holiday in all state government offices and educational institutions.