Prosecutors might face an uphill battle to secure a murder conviction if they were to bring firefighter Muhammad Adib Mohd Kassim's death to court, said a criminal lawyer.

M Hafiz Zainol Abidin said chances are slimmer as authorities could not confirm Adib's cause of death through the post-mortem.

"An inquest to determine Adib's cause of death means that pathologists who performed the autopsy on his body could not arrive as to cause of death.

"This would weigh a lot in a future criminal trial, if any, with regard to pinning the blame on anyone for murdering Adib. It is not impossible, but it will be a tough battle," he said when contacted today.

Hafiz said the post-mortem report holds an important key for any murder trial besides other evidence.

"When a case is being tried under Section 302 of the Penal Code for murder, the prosecution will have to prove that the victim had died due to injuries inflicted by the suspect in the first place.

"There is still the possibility that the inquest will find that Adib had died due to assault injuries but a defence lawyer can still argue using the autopsy report that medical examiners could not come to a conclusion as to what he died from."

The lawyer, who has 12 years of experience as a defence counsel, said another possibility from the inquest is that the coroner's court can deliver an open verdict.

In that case, he explained, the court could rule that the cause or circumstances of Adib's death remain unknown or are not clear.

"If the court delivers an open verdict, it would make it even tougher for the prosecution to secure a murder or even manslaughter conviction."

While stressing that these remain hypothetical and are not the general rules, Hafiz said there was a high possibility that any future criminal trial involving Adib's death could only go as far as manslaughter charges instead of murder.

This morning, the Shah Alam Coroner's Court set Feb 11 as the starting date of the inquest to determine what caused the 24-year-old firefighter's death.

Adib succumbed to his injuries at the National Heart Institute on Dec 17, 21 days after receiving treatment for injuries sustained during a riot at Sri Maha Mariamman Temple in Seafield, Subang Jaya.

It has been alleged that Adib was assaulted by rioters.

A post-mortem had been conducted by pathologists but Home Minister Muhyiddin Yassin had on Dec 27 announced that an inquest would be held to determine Adib's cause of death.