Former Jakarta governor Basuki Tjahaja Purnama, who is serving two years' jail for blasphemy, will turn down parole in hope of an early release.
The Chinese-Christian politician better known as Ahok will be eligible for parole next month and be released for up to four hours a day.
"He has decided not to take it and will wait until he is completely free," his sister, Ms Fifi Lety Indra, said in an Instagram post on Wednesday.
According to her, there is a chance that Basuki could be released as early as next month after having served almost two-thirds of his sentence and taking into account the possible remission he may be granted for good behaviour.
"But rather than (speculate), let's wait for the exact count in August," she added.
Local prison authorities confirmed that Basuki has served two-thirds of his sentence and has been "cooperative" during his time behind bars, although they would not comment if he has been granted parole yet.
An early release would cap what has been a trying couple of years for Basuki, who was sentenced to two years' jail in May last year after a Jakarta court found him guilty of blasphemy against Islam.
The controversial sentence was handed down weeks after he had lost the Jakarta gubernatorial election to Mr Anies Baswedan.
Prior to his downfall, Basuki was poised to make history as the first elected governor of Indonesia's capital Jakarta who is not only Chinese but also Christian. But his straight-talking manner and championing of pluralism, which endeared him to many, also saw his opponents turning that against him.
They pounced on a speech he made in September 2016, when he referred to the Quran and told constituents not to be deceived by his opponents who say Muslims cannot elect a non-Muslim leader.
Hard-line groups such as the Islamic Defenders Frontrallied hundreds of thousands of Muslims to take to the streets in protest.
Critics panned the heavier-than-expected sentence, saying the court had bowed to pressure from hardline groups.
In April, a court granted his request for divorce on grounds that there was adequate evidence of infidelity by Madam Veronica Tan, his wife of more than 20 years.
Basuki, who took over as Jakarta governor from Mr Joko Widodo after the latter was elected president in 2014, remains a popular figure.