Newly released prisoners in Queensland are breaching parole conditions so they can hide drugs internally on their return to jail, the union which represents the state's prison officers says.

Key points: The union representing prison officers says drugs being smuggled into jails is 'almost an industry'

The union representing prison officers says drugs being smuggled into jails is 'almost an industry' It says regulations prohibit officers from removing drugs from an inmate, even if guards can see them during a strip search

It says regulations prohibit officers from removing drugs from an inmate, even if guards can see them during a strip search Prisoner Legal Service Queensland says body scanners would be more effective in finding the drugs prisoners are hiding in their bodies

Michael Thomas, from the Together Union, said inmates were ingesting or inserting drugs to sell or distribute when they re-entered prison — and officers were battling to stop them.

He said the strategy of delivering drugs through the walls of prisons was "almost an industry".

"We know there's a big problem with people who have breached their parole, and they are having to do a stint in prison," Mr Thomas said.

"People know the penalty for breaching parole is to do a further stint inside — and it can be quite lucrative to take that risk.

"And in some cases, people are stood over and pressured to take that risk to bring drugs back into the system, effectively inside them."

Mr Thomas said regulations also prohibited officers from removing drugs from an inmate, even if guards could see them during a strip search.

"You can see evidence that they've secreted evidence within them," he said.

Michael Thomas warns prisons are overcrowded and officers' lives are at risk. ( ABC News: Mark Leonardi )

"The problem is, prison officers are prohibited by law from bringing that material out — it's prohibited by law."

He said the inmate would then be isolated, but that could be challenging with overcrowding issues at prisons.

''All the spare spots in the jail are used to house the 150 per cent over-capacity prisoners that we have," Mr Thomas said.

Full body scanners are used in prisons in Victoria and New South Wales, but not Queensland.

Helen Blaber from Prisoner Legal Service Queensland said such scanners would work better than strip searching.

''It's not as humiliating for a prisoner to experience a body scan and it's going to be a more effective way of identifying if there is a forbidden substance inside of a person,'' Ms Blaber said.

''I suspect body scanning is one of the priorities that are not being met, but there are many priorities not being met, and are being exacerbated by overcrowding in Queensland prisons.''

Under the Corrective Services Act, only a doctor can conduct a body search if an inmate is thought to have hidden something internally.

These are not the only ways that drugs enter the system.

The Crime and Conduct Commission's Taskforce Flaxton examined corruption in Queensland prisons last year and found "contraband", which included drugs, were brought in by visitors or ''mules'', prisoners, officers, dropped by drones and sent by mail.

It also found "instances of correctional officers supplying contraband to prisoners for payment and colluding to subvert search procedures".

Regulations prohibited officers from removing drugs from an inmate, even if guards can see them during a search. ( ABC News: Melanie Vujkovic )

Mr Thomas said there was no significant evidence in the report to suggest prison officers were responsible for drugs entering prisons.

A spokesman for Queensland Corrective Services said it had a range of ways to uncover material that could be taken into prisons.

''Personal searches, substance testing and regular random cell and area searches are all conducted to intercept and locate contraband,'' he said.

He also said those returning to prison after a short release ''face particularly careful monitoring and searching''.