The National Bureau of Investigation (NBI) has launched a backtracking probe into the activities of two suspects in the recent Bondi Beach shooting in Australia.

In a report by RH 15 Jecelle Ricafort, NBI Spokesperson Palmer Mallari said the agency is currently coordinating with the Bureau of Immigration (BI) and Armed Forces of the Philippines (AFP).

The bureau is verifying the possible areas visited by the father and son, as well as the individuals they may have spoken to or transacted with.

Mallari said authorities are not ruling out the possibility that the two underwent military-style training while in the Philippines, as suggested in some reports.

He stressed the importance of backtracking, noting that the suspects stayed in the country for nearly a month before heading to Sydney.

Naveed Akram, 24, who survived the encounter with law enforcement during the shooting, has been charged with 59 offenses, including 15 counts of murder and one committing a terrorist act, reported US media.