Jakarta – Indonesian police were holding the head of a Muslim cult on a preliminary charge of blasphemy after allegations that the group held rituals involving sex orgies and adultery, a police spokesman said on Sunday.

Agus Imam Solihin, head of the Satria Piningit Weteng Buwono sect, gave himself up to police last week after a raid on the cult's house. A former sect member accused the leader of proclaiming himself God and holding the bizarre sex rituals, Jakarta police spokesman Zulkarnain Adinegara said.

Authorities in Indonesia had been investigating the sect and police said Solihin faces five years jail if found guilty of blasphemy. Police usually classify a person a suspect in Indonesia before prosecutors may lay formal charges.

"If it is proved that Agus Solihin has proclaimed himself God and has restricted sect members from practicing Islam such as through praying it would be blasphemy," Adenegara said.

While Indonesia is the world's most populous Muslim country, its constitution protects freedom of religion and it has sizeable Christian, Hindu and Buddhist communities.

A range of sects have also flourished in a country known for its religious tolerance, but some have been clamped down on by authorities, particularly when there has been pressure from a small, but vocal radical Muslim fringe.

[Reporting by Telly Nathalia; Editing by Ed Davies and Louise Ireland.]