So if you are investigating what looks like organised crime in Papua New Guinea, he said, you are advised to look for external influences, particularly from Asia and certain parts of Australia.

He explained that in most countries mafia-like organisations extend their influence upwards into governments and businesses. This sort of corruption tends to work its way from the bottom up.

In Papua New Guinea, it tends to work differently. Here the mafia organisations target corrupt individuals at the top and once they have them in their pocket they use them to infiltrate the lower echelons of the organisation.

The corrupt politician, for instance, will corrupt the boss of his government department and this boss will corrupt senior staff under him. Sometimes this method seeps down and saturates entire departments.

So if you are going after organised crime in Papua New Guinea, Hari advised, start at the top.

I asked him whether this isn’t inherently very dangerous and he agreed but also pointed out that it had never really bothered him, it just made him ultra-careful and much more devious in the way he worked.

On the other hand disorganised crime, according to Hari, is everything illegal that happens either spontaneously or with very little planning.

Someone lashing out in rage and injuring or killing someone is a good example. Highway robbery carried out by gangs of raskols is another. A group of bored young men who decide to set up a roadblock and rob people is disorganised crime.

So is a murder committed during clan warfare or an assault committed against a spouse in the home.

Anything that a little forethought might have prevented if the consequences were properly considered is disorganised crime.

The ‘other’ category, the one that really fascinates Hari, usually involves something happening for no apparent reason and which, in fact, may or may not be a crime.

The discovery of the body of a ward councillor renowned for his bad temper in the shallow waters off Koki Market.

The mysterious disappearance of a university professor who may or may not have been murdered.

The apparent accidental hit and run of a novice politician outside the Ela Beach Hotel.

All good examples you may have heard about.

These sorts of cases used to really get Hari going and he would pursue them with a doggedness that often baffled those working with him (or who were nominally in charge of what he was supposed to be doing).

I think it was the mystery of these sorts of cases that Hari found attractive. They were puzzles that he couldn’t leave alone until he had solved them.

And often enough he discovered there was no real crime committed. For many policemen this would be disheartening but it wasn’t so for Hari.

Along the way he helped people with their problems, settled family squabbles that had been going on for years and even redirected individuals away from actions that might otherwise have led them to commit a crime.

On Hari’s ‘other’ list were also crimes that were on the books but which he thought were non-crimes or so trivial they were worth worrying about.

Among these was homosexuality, which is illegal in Papua New Guinea. What consenting adults did in private, as long as they didn’t hurt anyone else, was none of his business he reckoned.

Solving a crime that was never committed, Hari said, left him smiling for days on end.