Subhashree Das, wife of Maoist leader Sabyasachi Panda, was released on Tuesday from a jail in Orissa after a court acquitted her in a 2003 shootout case for lack of evidence.
Her release was sought by the rebels in exchange for an Italian who has been held captive by them since last month.
A fast track court at Gunpur in Rayagada district acquitted Das, whose husband was behind last month's abduction of two Italians, one of whom was later released.
Das was accused of involvement in a gun battle between Maoists and police in Kutingaguda in 2003.
After coming out of jail, Das said the government did not have any role in her release.
"I was saying from the beginning that I am innocent. Now it was proved," she told reporters in Gunpur, about 250 kms from here.
Praising her husband for serving the poor and peasants, she said Panda was a friend, guide and philosopher for her though he stayed away from her. Das also feared that police may arrest her again.
Das, also known as Mili, is one of several prisoners whose freedom was sought by Maoists in exchange for Italian tour operator Bosusco Paolo, who the rebels abducted March 14.
Panda is organising secretary of the Odisha unit of the Communist Party of India-Maoist (CPI-Maoist), which kidnapped the Italians.