President Rodrigo Duterte on Thursday said he will order a reinvestigation into the Mamasapano clash which left 44 elite policemen hunting down a terrorist dead.

“Forty-four Mamasapano soldiers, they went inside, they died,” Duterte said in front of Filipino and Chinese businessmen in Beijing.

“No dramatics, no nothing. No...Except that we grieve for our soldiers. Maybe in this --- in the days ahead, I will order the opening of that issue again.”

Duterte said he wants a reopening of the probe to specifically know what happened to the $5 million reward the US offered for the arrest of Malaysian bomb maker Zulkifli bin Hir, alias Marwan.

“Not really to prosecute people but just to know what happened? Who got the five million?” Duterte said.

“Whether the tip of the finger of Marwan, was gotten by the Special Forces of United States or was it really brought to the forensic division diyan sa Crame.”

Marwan was killed in the January 2015 operation, but at the expense of 44 Special Action Force (SAF) troopers who clashed with private armed groups, the Bangsamoro Islamic Freedom Fighters (BIFF), and even the Moro Islamic Liberation Front (MILF), which at the time was at the height of peace negotiations with the government.

A source earlier told ABS-CBN News that a DNA sample taken from Marwan matched that of Marwan's brother who is in Guantanamo Bay.

The US Federal Bureau of Investigation reportedly conducted the DNA test.

• READ: Marwan is dead; DNA matches brother's: source