President Rodrigo Duterte has assured justice will be served to UST law student Horacio Castillo III, who allegedly died of hazing last month.

"You have my word," Duerte told Castillo's parents, Horacio Jr. and Carmina, whom he met in Malacanang on Wednesday afternoon.

He said those responsible for the death of Castillo could be charged with murder because he was "helpless" when he allegedly underwent initiation rites of the Aegis Juris Fraternity.

Duterte said there was no need to cancel the passport of those allegedly involved on Castillo's death.

He expressed belief the "persons of interest" are on the Immigration watch list.

"So all the suspects who may have been involved in the commission of murder, their names were already posted hopefully by this time in all ports of entry and exit dito sa Philippines," Duterte said.

An autopsy indicated that Castillo died of heart attack due to injuries he sustained. The Department of Justice is investigating the case. Celerina Monte/DMS