Sacked All India Anna Dravida Munnetra Kazhagam (AIADMK) leader V. K. Sasikala was on 6 October granted five-day parole to visit her ailing husband M. Natarajan in Chennai.
74-year-old Natrajan had undergone a dual organ transplant.
Earlier in the day, Sasikala's lawyer Krishnappan said the jail authorities received an e-mail from the Chennai Police Commissioner agreeing to grant parole.
On Tuesday, the Karnataka Prisons department had rejected Sasikala's parole application.
Prison authorities said her plea was not backed by a legally approved health certificate stating that her husband was unwell.
Sasikala had requested parole for 15 days to attend to her husband. Her husband has been hospitalised for the last nine months due to kidney and liver ailments.
Sasikala has been lodged in a Bengaluru prison since February 2017 after being convicted in a disproportionate assets case.