The leader's son, Arvinder Singh Lovely Sidhu took to Facebook to inform about his father's passing. "My father, Buta Singh passed away today morning. May Waheguru bless his soul," his post read (roughly translated from Hindi).
Reacting to the sad news PM Modi expressed his condolences on Twitter.
Congress leader Rahul Gandhi condoled the minister's death as well and said he was a loyal leader who devoted himself to the country.
"The country has lost a true public servant and a loyal leader with the death of Sardar Buta Singh Ji. He devoted his entire life for the service of the country and the well being of the people, for which he will always be remembered," Gandhi said.
Rajasthan Chief Minister Ashok Gehlot expressed grief at the demise of the Congress leader and extended condolences to his family.
"Sad to learn about the demise of a former union minister, senior Congress leader and former MP from Rajasthan, Shri Buta Singh ji. My heartfelt condolences to his family members in this difficult time, may God give them strength to bear this loss. May his soul rest in peace," Gehlot wrote on Twitter.
Singh fought his first elections as an Akali Dal member and joined the Indian National Congress in the 1960s. He was first elected to the 3rd Lok Sabha in 1962, from the Sadhna constituency. He was the Union Home Minister from 1986-1989 in the Rajiv Gandhi government. Before that he held the position of Agriculture Minister from 1984-1986 under Rajiv Gandhi's leadership.
He was the Chairperson of the National Commission For Scheduled Cast from 2007 to 2010.
He also authored a collection of articles on Punjabi literature and Sikh history and a book called Punjabi Speaking State (a critical analysis).