Shahbaz Hussain -- who was acquitted by a special court here on Wednesday in the 2008 Jaipur serial bomb blast case -- was accused of sending emails claiming responsibility for the attack on behalf of terror outfit Indian Mujahideen.
Hussain was picked up by police from Lucknow in August, 2008 and had been in judicial custody in Jaipur since then.
Suresh Vyas, amicus curiae for Hussain, said allegations against him could not be proved.
"He was accused of sending emails and there was no other charge against him. The charge of sending email could not be proved against him. He has been under judicial custody since August 2008, Vyas said.
Five persons were arrested in connection with the Jaipur blasts. Four of them -- Mohammad Saif, Mohammad Sarwar Azmi, Mohammad Salman and Saifurrehman-- were convicted by a Jaipur court.
Apart from these five, three accused involved in the blast - Shadab, Mohammad Khalid and Sajid - are still absconding while two accused, Mohammad Atif and Chhota Sajid -- were killed in the Batla house encounter in Delhi in September 2008.
The serial blasts had rocked Jaipur on May 13, 2018. The blasts took place at Manak Chawk Khanda, Chandpole Gate, Badi Chaupad, Chhoti Chaupad, Tripolia Gate, Johri Bazar and Sanganeri Gate, all inside the walled city of Jaipur which left 70 people dead and 185 injured.