"It was purely based on humanitarian grounds. The granting of the clemency is certainly considered by the President as a reasonable one," Jusuf Kalla said here on Thursday.
The vice president noted that the appeal for clemency was made a long time ago.
"Lately, the requirements for such an appeal were fulfilled," he pointed out.
The presidential decree reduced the sentence by six years.
President Joko Widodo (Jokowi) had earlier granted clemency to Antasari Azhar, Antasaris lawyer Boyamin Saiman stated here on Wednesday.
"This morning, I received information from the state secretariat that clemency has been granted to Antasari Azhar," Boyamin confirmed in a short message sent to the Antara news agency.
He added that he will seek confirmation from the South Jakarta district court and will see the letter himself.
As per procedure, information about clemency was to be sent by the presidential office to the South Jakarta district court, he explained.
Antasari was released on parole from the Tangerang prison on November 10 last year after he had served two third of his jail term, starting May, 2009.
He was convicted and sentenced to 18 years after being found guilty of masterminding the murder of Nasrudin Zulkarnaen, Director of Putra Rajawali Banjaran.
His appeal to the higher courts failed and an attempt for a review of his case was rejected under the previous regime.
Antasari has continued to maintain that he was innocent and observers emphasized that there were irregularities in the charge against Antasari.(*)