At least one person each day has been killed by police or roving gangs in the Philippines following the election of firebrand Filippino president-elect Rodrigo Duterte, as new details of the country's vigilante culture emerge.

There have been roughly 60 killings in the country since Duterte, who has promised an extraordinary crackdown on crime, was swept to power on 9 May, Reuters reported.

The former mayor of Davao City is to be inaugurated to the Filipino presidency on 30 June but, according to Chito Gascon, head of the Commission on Human Rights (CHR), his rhetoric and promises have already instilled a sense of impunity among the police.

In a show of the extent of the growing sense of that impunity, those executing drug dealers in the country and other alleged criminals have taken to leaving hand-written notes on their corpses.

"Basically, you have Mr Duterte saying: 'It's ok, I've got your back'," Gascon was quoted by Reuters as saying.

In a recent show of his intention, Duterte travelled to a northern province to give a $6,000 (£4,481) reward to police who had executed a drug lord.

When he was previously asked what would happen to criminals once if he became president, Duterte suggested the number of fatalities would rise and crime would decrease.

He said: "The 1,000 [I allegedly killed] will become 100,000. That will fatten the fish in Manila Bay. I will dump their bodies there."

However, in the Philippines, which is seen by some analysts to be on the verge of becoming a narco state, the spate of killings may indicate police are cleaning up before Duterte comes to power.

Duterte's pick to be the country's police chief, Ronald dela Rosa, said the slayings may have been carried out by officers in league with dealers who are covering their tracks.

Rodrigo Duterte, Philippine presidential candidate
Former mayor of Davao City Rodrigo Duterte is to be inaugurated to the Filipino presidency on 30 JuneRomeo Ranoco/Reuters