The Christian former governor of Jakarta in Indonesia, Basuki Tjahaya Purnama – known as Ahok – has been released from prison after serving time for insulting the Quran.

Ahok was jailed in May 2017 following his comment that political rivals were deceiving people by using a verse in the Quran to say Muslims should not be led by a non-Muslim.

Later, an incorrectly subtitled video of the comments went viral, eventually leading to his defeat at the polls and his imprisonment on charges of blasphemy.

Hundreds of thousands of Muslim protesters took to the streets, led by hardline Islamist groups. One protester died and police officers were injured.

In a letter to his supporters this week, Ahok asked people not to hold a parade to welcome him for the sake of public order, or to camp out in front of the prison. He said: 'I am very thankful to God for allowing me to spend time in prison.'

He also urged his supporters not to give up on politics, saying of the forthcoming April elections: 'I strongly urge all my fans not to abstain from voting.'

Many fear the elections may also be tainted by the religious and racial tension that marred the Jakarta governor race two years ago.

Ahok is widely popular among progressive Indonesians, who fear his trial and sentence indicates growing intolerance in the country.

In 2017, when Ahok was imprisoned, Indonesia was number 46 on the Open Doors World Watch List. It now sits at number 30. Although Indonesia's constitution promotes religious freedom, Islamic extremist groups are becoming more influential.

Some regions of Indonesia already operate under Islamic Sharia law. According to Open Doors, believers from Muslim backgrounds often face persecution from their families and communities and are put under pressure to renounce their faith.

In 2018, 18 Christians were killed and many more wounded in a co-ordinated suicide bomb attack on three churches in the city of Surabaya.

An ethnic Chinese Christian, Basuki Tjahaja Purnama, 52, lost a 2017 bid to be re-elected governor over charges of insulting the Quran that brought hundreds of thousands of Muslim protesters to the streets, led by hardline Islamist groups.

'My dad's a free man! Thank you everyone for the support,' his son, Nicholas Sean, said on social media app Instagram, alongside a selfie with his father.

Months of protests and a polarising election preceded Purnama's jailing in May 2017, raising concerns over the erosion of Indonesia's long-held reputation for pluralism and tolerance, and the creeping influence of Islam in politics.

'(Purnama's) prosecution showed non-Muslims and many Muslims that the freedoms of expression and religion in Indonesia are tenuous,' New York-based Human Rights Watch said.

Purnama's troubles started with comments that political rivals were deceiving people by using a verse in the Quran to say Muslims should not be led by a non-Muslim.

Later, an incorrectly subtitled video of the comments went viral, eventually leading to his defeat at the polls and his imprisonment on charges of blasphemy.

As a figure with a no-nonsense reputation for cutting through red tape while in office, he remains popular with progressive Indonesians.

'We support him, not because of his religion or beliefs, but because of his good work,' said one of this Muslim supporters, Siti Afifah, who had waited outside the prison for his release.

But Ahok, as he is popularly known in Indonesia, is unlikely to re-enter politics any time soon, media say.

His representatives say he is considering launching a talk show and running his family's oil trading business.

Last week, in a letter from behind bars, Purnama said he now wanted to be known by his initials 'BTP', and apologised to those hurt by his remarks when in office.

He also urged supporters to exercise their right to vote in April's presidential election, which many fear may also be tainted by the religious and racial tension that marred the Jakarta governor race two years ago.

President Joko Widodo – once a steadfast ally of Purnama's – is running for re-election against retired general Prabowo Subianto. Prabowo endorsed the massive protests against Purnama two years ago and backed the winning ticket in that election.

Additional reporting by Reuters.