THREE out of four people arrested and detained by police in Darwin (Australia) are under the influence of illicit drugs, research shows.

Australian Institute of Criminology data reveals 73 per cent of Darwin detainees tested positive to cannabis in July and August, steadily increasing from 46 per cent in January last year.
Another 8 per cent tested positive to methylamphetamine, the drug commonly known as speed.

The data, compiled under the AIC's Drug Use Monitoring in Australia program (DUMA), shows a steady increase in the number of offenders testing positive to cannabis.

Drug Free Australia executive officer Jo Baxter said there was a common misconception that cannabis was a "soft" drug.

"Research now shows just how complex and dangerous this drug is," she said.

She said Australian Governments needed to be tougher on illicit drugs.

"Then, and only then, will we begin to get the results similar to those countries that have been successful reducing illicit drug use," she said.

But NT police say alcohol is a far bigger problem than any illicit drug when it comes to crime.

Officer-in-charge of the NT Police Drug and Alcohol policy unit Sgt Scott Mitchell said the statistics for cannabis use among Darwin offenders were not significantly different to the rest of Australia, but they were for alcohol.

Our cannabis figures aren't alarming (by comparison) but there's a significant difference in the alcohol figures," Sgt Mitchell said.

DUMA statistics also showed 83 per cent of female offenders and 82 per cent of male offenders had reported heavy alcohol use at some time in the 30 days before their offence.

This figure was far higher than anywhere else in the country.

"It's that really high level of drinking and offending that's the problem," said Sgt Mitchell.

"People when they get drunk do dumb things. They get into cars and drive. We know they shot someone because they looked at their girlfriend.

"Cannabis users, by and large, are fairly mellow."