Nalini, serving a life term in the Rajiv Gandhi assassination case, on Monday began an indefinite fast at the high security Vellore prison, demanding her premature release.
She has refused to eat since this morning, demanding that an advisory board to decide on her premature release be set up at the earliest, a prison official said.
"Though the prison authorities tried to dissuade her, she has refused to take her food since this morning", Superintendent of Police, Vellore prison, Jayabarathi told PTI over phone.
Nalini, who has been convicted along with her husband Mururgan in the case, had recently moved the Madras High Court, seeking a direction to the state government to release her.
Nalini, who has served over 18 years in Vellore prison, in her petition claimed she was required to complete 14 years of imprisonment for being entitled for premature release under Section 433(A) of CrPC.
Since June 18, 2005 she has been entitled for premature release, she contended in her petition.
The government had not constituted a fresh advisory board to consider her plea, despite the High court's direction last year, she alleged.