Malaysian militant Dr Mahmud Ahmad is presumed to be dead as he is no longer seen in Marawi, Philippines, or on social media, Defence Minister Hishammuddin Hussein said today.

At the same time, Hishammuddin told a press conference in Kuala Lumpur that final confirmation from Malaysia can only be made once Mahmud's remains have been found and matched with DNA retrieved from his family members.

"We can't confirm his death until his body is found, that's (the) fact. It could be part of their strategy too (to hide the body).

"But (also) the fact that he has not been seen sending orders out on social media, the fact that he has not been seen in Marawi, the fact he has not been bragging on social media that he's still alive, we assume he is no longer effective," he said.

"If not effective, we can assume that he is dead until the body is found and matched to DNA from his family members, for the final decision," he said when asked whether Malaysian intelligence has confirmed Mahmud's death, as reported by Philippine authorities.

Mahmud, a former lecturer, had reportedly died on Oct 19 in Marawi and was identified as a leader of Islamic State operatives fighting in the area.

Hishammuddin, however, today reassured that IS presence in the conflict area has been curtailed by local authorities.

"I can confirm that the presence of IS in Marawi is no longer in existence," he said.

The Battle of Marawi is an armed conflict in Marawi, Lanao del Sur, that started on 23 May 2017 between Philippine government security forces and militants, including the Maute and Abu Sayyaf groups.