Jakarta. A pro-democracy group has lashed out against what it called "unprofessional conduct" by prosecutors in the blasphemy case against Jakarta Governor Basuki "Ahok" Tjahaja Purnama.

Prosecutors announced that they have completed a study of the case dossier just three days after receiving it from police investigators, and handed over the files to the court only a few hours later.

Ahok's trial will commence on Dec. 13.

According to the Setara Institute, a Jakarta-based nongovernmental organization that conducts research and advocacy on democracy, human rights and political freedom, the speed at which prosecutors completed the 826-page dossier shows that they were not serious in examining it.

"Prosecutors did not play their role as supervisors; they merely delivered the dossier to court," Setara Institute chairman Hendardi said on Tuesday (06/12).

"There should have been a thorough examination to identify potential errors. It is apparent that both the professionalism and impartiality of prosecutors are questionable," he added.

A doctored video of a speech Ahok made on Pramuka Island in Jakarta's Thousand Islands district in September went viral and prompted several Muslim groups to report him to the police for blasphemy.

Police named the governor a blasphemy suspect last month amid mounting pressure from hardline Muslim groups and a series of mass protests demanding his immediate arrest.

"If public pressure can influence law enforcement, the justice system is in peril," Hendardi said.