Queensland taxpayers are forking out hundreds of thousands of dollars a year to clean up clandestine drug laboratories found in government housing, but offending tenants are not being banned from reapplying for a house.

Key points: Cleaning up public housing drug labs cost Queensland taxpayers $556,500 over two years

Cleaning up public housing drug labs cost Queensland taxpayers $556,500 over two years Tenants linked with illegal drug labs are evicted, but not banned from public housing

Tenants linked with illegal drug labs are evicted, but not banned from public housing State Opposition said Government was going soft on offenders

New figures obtained by ABC News show taxpayers paid more than $550,000 over the past two financial years to decontaminate about 140 houses across Queensland.

The information, sourced under Right to Information, shows 53 houses were found with illegal drug labs in the last financial year, costing $224,500 — a decrease from 2016-17 when 89 labs were found in public housing with a clean-up cost of $332,000.

But a Department of Housing spokesman said while tenants are expected to act responsibly, the tenant is not prohibited from reapplying for a property under the public housing policy.

"If a tenant is found to be responsible for the illegal manufacture of drugs, eviction proceedings are commenced," he said.

"The tenant is not prohibited from applying for public housing again, but they must pay any outstanding debts to the department and be assessed on merit.

"The health and safety of our tenants is paramount, which is why they are asked to adhere to the Fair Expectations of Behaviour policy."

The geographical area of Brisbane had the highest decontamination costs over the past two years compared with other Queensland regions.

Unidentified chemicals found in a Queensland drug lab. ( ABC News: Kristian Silva )

'Obscene amount of money': Opposition

State Opposition Leader Deb Frecklington said the policy was going "soft" on offenders.

"We believe that public housing is a privilege, not a right," she said.

"Queensland taxpayers shouldn't have to foot the bill because Labor are soft on bad public housing tenants who don't deserve to be there, especially those running drug labs.

"Over $500,000 to clean up meth labs in the last two years is an obscene amount of money.

"The system is there to ensure our most disadvantaged Queenslanders have a roof over their heads, not to make cash on the side."

There are more than 60,000 public housing properties in Queensland.

Warning for private owners

The Real Estate Institute of Queensland (REIQ) is also encouraging landlords and agents to have their properties tested for chemical residue left over from suspected home drug laboratories.

Julieanne Worchurst from REIQ partner Smoke Alarm Solutions said her company conducted up to 30 tests a month across the state, for homeowners worried their properties may be contaminated after a vacancy.

"The issues that we're seeing through methamphetamine screening and testing through our laboratory system is not contained to the inner city," she said.

"It is just as much a problem in the regional areas of Queensland and elsewhere in the country.

"The residue is retained until it's cleaned, so this could go on for multiple years."

The company says about half of the 400 homes it tested in Queensland this year have tested positive for methamphetamine residue.

The highest number of positive readings were from tests in Redland, Logan, Yarrabilba and the Sunshine Coast.

"As the Australian Crime Commission has pointed out, 0.5 micrograms and above can be considered harmful for health."