Indonesia’s blasphemy law has once again come under scrutiny after former vice-president Jusuf Kalla was reported to police over remarks linking past Muslim-Christian conflicts to beliefs about martyrdom.

The case is unusual because it involves Christian complainants against one of the most senior Muslim figures in the world’s most populous Muslim-majority nation and reflects what critics have long called the law’s central flaw: its susceptibility to politicised use.

Kalla, a career politician who no longer holds public office, was reported by several Christian and Catholic youth groups in mid-April over comments made during a public lecture at Indonesia’s Gajah Mada University last month.

As part of the address to university students, Kalla referenced historic sectarian conflict in Indonesia, including in Poso in Central Sulawesi and Ambon in the Malukus, two sites associated with deadly Muslim-Christian violence.

“Why do religions easily become a reason for conflict, like in Poso and Ambon? Because both Muslims and Christians believe that killing or being killed can be considered martyrdom,” he said.

The Poso clashes involving Muslim and Christian religious groups lasted from 1998 to 2001 and reportedly left more than 1,000 people dead. The religious riots in the Malukus from 1999 to 2002 caused at least 5,000 deaths.

“During conflict, both sides hold that belief. If I kill a Muslim, I become a martyr. If I die, I also become a martyr. That makes it difficult to stop,” Kalla said, with footage of the speech going viral on Indonesian social media.