Drugs are increasingly being found in south-east Queensland prisons as Corrective Services staff struggle to detect illicit substances, a union says.

Figures tabled in State Parliament show prison officers have increased the number of targeted and random drug tests over the past three years to crack down on banned substances behind bars.

Of the more than 4,800 targeted drug tests carried out in Queensland prisons in the 2015-16 financial year, almost 800 — nearly 17 per cent — returned positive.

The Maryborough Correctional Centre in the Wide Bay Burnett performed worst, with 22 per cent of targeted tests coming back positive, up from 17 per cent in 2014-15.

The Brisbane Correctional Centre also had an increase in positive results at 20 per cent, up from 11 per cent the previous year.

But other prisons had a fall over the period, with 18 per cent of targeted tests at the Arthur Gorrie Correctional Centre near Ipswich returning positive, down from 25 per cent.

The privately-operated Southern Queensland Correctional Centre in the Lockyer Valley, also had a fall from more than 27 per cent to 20 per cent.

“As we see more chemically-created drugs and the problems that go along with them … things like the urine analysis are finding them, but once we get to that point they’re already inside the prison which is a worry.”

Mr Thomas said it was a “systemic issue”, and drug detection methods may need to be re-examined.

“We’re seeing an increase in the number of tests, and that’s a good thing because we’ve got an increased number of prisoners that are in jail,” he said.

“But are the tools that we’ve used in the past such as the drug detection dogs, are they appropriate now with the changing nature of drugs in our society?”

The Department of Corrective Services has been contacted for comment.

Source: http://www.abc.net.au/news/2016-12-06/drug-detection-in-queensland-prisons-needs-rethink-union-says/8096318