Tasmania's police association has raised concerns about the safety of prisoners in transport vans, warning it is only a matter of time before someone dies.

Key points: Tasmania's police union believe prisoner transport vans remain unsafe despite coroner recommendations

Tasmania's police union believe prisoner transport vans remain unsafe despite coroner recommendations They say the cage-like pods do not have restraints making them dangerous if there's an accident

They say the cage-like pods do not have restraints making them dangerous if there's an accident The police department does not share the union's concerns but it looking for better vehicles for long distances

In 2014, Troy Colin Monson took his own life in the back of a corrections van taking him from Launceston to Hobart.

His death was not discovered until the van arrived at Risdon Prison.

In an inquest finding, coroner Simon Cooper ruled that despite being a suicide risk, the 42-year-old had not received an acceptable standard of care.

He also recommended the purchase of an appropriate vehicle "to enable special escorts to be safely carried out" and the fitting of specialised seatbelts.

But the Police Association says the same issues identified in corrections vans were present in the police vans used to transport prisoners across Tasmania.

The union said the police vans lacked any type of buffer or restraint to protect detainees if the vehicle rolled in icy conditions.

"People could be in them for two to three hours travelling those long distances, particularly on the west coast there's wet, icy conditions," Mr Riley said.

"If the vehicle rolls there is no protection for those people in the back of that vehicle."

Seatbelts are not fitted to vans used to transport inmates because they pose a risk of self-harm. ( Supplied )

Among the union concerns are:

• The cage-like set up with no restraints, leading to higher injury risk during an accident • The detainee has to either sit, crouch with legs stretched or lie down • Cameras have been fitted to monitor but cannot record, leaving officers at risk if there is an inquest or complaint • If there is an emergency stop, officers are required to enter the cage to extract the person (increasing the risk factor to the officers) • A lack of heating in the rear

The vans are also used to transport those in custody for mental health assessment.

"If your son or daughter has to be transported for mental health assessment and they were not compliant, these vehicles and the rear cage that they would be held in, are not satisfactory to transport them over long distances for two to three hours," Mr Riley said.

The union said it had raised the issue with management at least twice.

"The recommendations of the coroner apply not only to those [corrections] vehicles, but also the vehicles that are used by Tasmania Police," Mr Riley said.

Vans used limited speed limit for safety

The department said the union had raised concerns about long distance transports taking officers away from front-line duties, but Tasmania Police Assistant Commissioner Richard Cowling said it was the first time the union had raised prisoner safety.

"They haven't said to us it's a dangerous vehicle, what they're saying is it takes time for the members to drive … that's a bit different sort of discussion," he said.

Part of the reason long-haul trips take so long is officers have to drive under 80 kilometres per hour if they have a prisoner onboard.

"The vans are roadworthy, we limit them to 80 kilometres an hour specifically just to make sure that they are extra safe but the members certainly haven't had that discussion," the Assistant Commissioner said.

The issue of the divisional vans was put to Commissioner Darren Hine during budget estimates hearings in June this year.

Mr Hine said Tasmania Police had been reviewing its prisoner transport vehicles, especially over longer distances.

"For longer distances I understand they are not appropriate because you want the safety mechanisms in the back of those pods for longer distances," Mr Hine told budget estimates.

"My expectation would be early next financial year, as in past July. But we certainly do not want to wait too long. We understand some of the issues and the longer distances these prisoners have to be transported."

Tasmania Police last month unsuccessfully trialled a protective plastic screen or barrier used by police in Queensland.

It would have allowed some prisoners to be transported in the back seat of a police car, while still ensuring officer safety.