JAKARTA -  Jakarta’s Christian governor was formally named a suspect in a blasphemy investigation Wednesday, after allegations that he insulted Islam sparked a violent mass protest by the Muslims in the Indonesian capital.

Police said the allegations against Basuki Tjahaja Purnama, who is also the first member of Indonesia’s ethnic Chinese minority to lead Jakarta, should go to trial and ordered him not to leave the country.

Religious groups had demanded that Purnama, known by his nickname Ahok and Jakarta’s first non-Muslim leader in half a century, be prosecuted for allegedly insulting the Holy Quran while campaigning in elections for the governorship.

The governor - currently favourite to win the polls - had accused his opponents of using a Quranic verse, which suggests Muslims should not choose non-Muslims as leaders, in order to trick people into voting against him.

The blasphemy allegations sparked much anger among Muslims - both moderate and hardline - and more than 100,000 protesters took to the streets in Jakarta on November 4 demanding that Purnama be prosecuted, with the demonstration later turning violent.

After a lengthy investigation that involved questioning scores of witnesses, national police chief detective Ari Dono told reporters: “Basuki Tjahaja Purnama has been named a suspect.”

National police chief Tito Karnavian conceded there were “sharply dissenting opinions” and the decision was not unanimous, but added investigators had eventually concluded the case should go to trial.

Naming someone a suspect is a formal step in the Indonesian legal system that means authorities believe they have enough preliminary evidence to consider filing charges.

Purnama, who could be jailed for up to five years if found guilty under Indonesia’s tough blasphemy laws, pledged not to pull out of the Jakarta election in February following the announcement.

“This is not the end, there will be a court process which we hope will be open,” he said, urging his supporters to back him in the vote.

A spokesman for President Joko Widodo, an ally of Purnama, urged all involved to respect the legal process.