Philippine President Rodrigo Duterte is unlikely to stand trial in his remaining few months in office for crimes against humanity over his so-called war on drugs, but bereaved families of the victims said they will continue to fight it out whether in an international or a domestic court.

Duterte, whose populist campaigns since taking office in 2016 included the brutal anti-drug war, has claimed he had so many dead bodies of narcotics offenders dumped in Manila Bay that the "fish will grow fat." He recently said he wants his successor to continue "killing" them to stop substance abuse.

With the May 9 presidential elections looming, survey front-runner Ferdinand Marcos Jr. and closest rival and opposition icon Vice President Leni Robredo both said they will carry over the anti-drug campaign but with emphasis on prevention and rehabilitation.