"There have been no violations by her during the parole period," he said.
Also called the Parappana Agrahara Central Prison, the jail is located in the southern outskirts of the city.
Sasikala, 60, was granted a five-day parole on October 6, and had to return to the prison by October 12 evening, as directed by the jail authorities.
During the parole period she had visited Geneagles Global Hospital in Chennai where her husband Natarajan, 74, had undergone liver and kidney transplant last week.
Though Sasikala applied for 15 days parole last week, the prison authority had permitted her to be out of jail for only five days with conditions.
She had been directed to restrict her visit to Chennai and refrain from speaking to media or taking part in any political activities during the parole period.
A close confident of late Tamil Nadu Chief Minister J. Jayalalithaa, Sasikala is serving a four-year sentence since February 15 after the Supreme Court on February 14 upheld her conviction in a corruption case by a trial court in September 2015 here.
Sasikala's co-convicts Elavarasi (sister in-law) and V.N. Sudhakaran (nephew) are also serving the sentence concurrently in the same jail after they were held guilty in the Rs 64 crore disproportionate assets case of late Jayalalithaa.