But away from the political ping pong, the decision has been greeted with dismay by the Krishnaiah family, for whom it has reopened old wounds.

Mrs. Krishnaiah told me she had met her husband, who was from a poor Dalit (formerly untouchable) family, at college in the southern city of Hyderabad in 1981. They fell in love and married five years later. At the time of his murder, they were raising two daughters who were four and five-and-a-half.

A day after his death, she moved back with her children to Hyderabad where she took up a job as a college teacher to support the family.

Singh's conviction and sentencing had brought her some solace, but to see him walk out of prison has left her heartbroken and distraught.

“My husband was a government officer. He was killed while working. How can they set free his murderer? The government should reconsider the decision,” she said.

“This will send wrong signals to the society and encourage criminals. They will now think that even if they commit a heinous murder, they will go free.”

Mrs. Krishnaiah said she had appealed to the prime minister and the president, seeking their intervention to send her husband's murderer back to prison.

On Thursday morning, hours after Singh walked out of prison, her daughter Padma told news agency ANI that the family was “disheartened”.

“I request Chief Minister Nitish Kumar to give a second thought. His government has set a wrong example. It is unfair not just to a family but to the whole nation," she said, adding that they would appeal against the decision in court. (BBC)