Over 200 academics, writers, artists and filmmakers have written to President Pranab Mukherjee saying that he erred over the hanging of Afzal Guru and expressed deep "anguish and outrage".
In the letter submitted to the president Wednesday, they said, "We believe that you made a grave error in rejecting the mercy petition."
"If you had perused the trial court records and the lengthy documentation put together over the years by lawyers and civil rights activists, or even the Supreme Court judgment which sentenced Afzal to death, you would have known that his guilt was never established beyond reasonable doubt," the letter said.
"We write to you in deep anguish, despair but in outrage as well. Afzal Guru was hanged on February 9 in secrecy. We have been told - after the hanging - that you rejected the mercy petition filed by Guru's wife Tabassum on February 3," they said.
The letter claimed that as in life, Guru was denied his legal rights in his death. "Sir, every convict whose mercy petition has been rejected by the president, is entitled yet to a last resort."
"The convict has the constitutional right to file a judicial review or a delay petition, in the high court and the Supreme Court, to seek commutation of the death sentence," the letter said.
"Under the law, Afzal Guru may have lived still despite your rejection of the mercy petition, had he, his family and lawyers been informed of the rejection of the mercy petition. But perhaps fearing precisely this, the state whose head you are, sir, chose to execute him in secrecy," it said.
The academics asked for an explanation for the urgency in execution of Afzal Guru. "The Indian state must explain why it displayed such urgency in executing Afzal before those others whose mercy petitions your office has earlier rejected."
Afzal Guru was hanged in Tihar Jail on February 9 for his role in the December 13, 2001, Parliament attack.