KUALA LUMPUR, Malaysia (AP) — A Sikh family lost a court battle Monday in Muslim-majority Malaysia for the right to cremate one of their relatives after officials said the man had converted to Islam years before his death. The case threatens to revive complaints among non-Muslims that their religious rights are being sidelined — a grievance that has sparked interfaith tensions and severely eroded minority support for the government. The family of Mohan Singh has been fighting Islamic authorities for custody of his body after Mohan, 41, died of a heart attack on May 25. Officials from the Islamic government department of central Selangor state insisted Mohan converted to Islam in 1992, but the family said he practiced the Sikh religion until his death. Malaysia's secular High Court ruled Monday that it had no jurisdiction in the case, saying that the matter of Mohan's conversion to Islam had already been decided by the Islamic Shariah court, said the family's lawyer, Rajesh Kumar. Islamic authorities were expected to bury the body later Monday according to Muslim rites, since the Shariah court had already declared Mohan as a Muslim last month, Rajesh said. Malaysia has a double-tier court system for civil matters — Muslims go to the Shariah court; non-Muslims go to secular courts. But in interfaith disputes, non-Muslims complain they lose out as Shariah courts get the final say and rarely rule in their favor. The government has pledged to tackle legal ambiguities related to religious conversions. Authorities recently said minors can no longer be converted without both parents' consent, but the decision has not been made legally binding. Officials have not announced any new proposals to resolve disputed conversions in cases where someone has died. Ethnic Malay Muslims comprise nearly two-thirds of Malaysia's 28 million people. Minorities include ethnic Chinese and Indians who are mainly Buddhists, Christians, Hindus and Sikhs.