The Territory’s anti-corruption watchdog has launched an investigation into non-compliant buildings owned or leased by the NT Government, following his initial investigation into safety issues at TIO Stadium, that will include schools, Holtze prison and the Royal Darwin Hospital.

Independent Commissioner Against Corruption Michael Riches issued a statement Friday afternoon announcing the joint investigation with the NT Ombudsman after he said he was made aware “there may be more than 300” public buildings that are not properly certified.

The joint investigation will look at why landmark buildings or structures do not comply with occupancy certification requirements under the NT Building Act, including Parliament House, Holtze prison, the Royal Darwin Hospital, the Darwin Entertainment Centre, “as well as numerous public schools and police stations”.

“The Ombudsman and I have determined to jointly investigate the extent of non-compliance and why and how this has occurred,” Mr Riches said in the statement.

“We want to hear from any person, particularly those who work in building, certification and building insurance industries, who might have information relevant to this investigation.”

It is unclear how Holtze prison could be uncertified considering it was only completed in 2014.

While the buildings mentioned by Mr Riches may have historic non-compliance issues, TIO Stadium was recently identified as posing an immediate safety risk to the public after numerous issues were raised concerning unresolved fire safety problems, including insufficient fire hydrant water pressure and inconsistent use of the fire alarm systems.

In June, firefighters raised their concerns about safety issues at the stadium which led to fire service executives and government officials scrambling ahead of an AFL game to bring in extra measures to protect firefighters and the public.

However, instead of fixing all of the outstanding safety issues, Infrastructure Minister Eva Lawler extended the certification exemption declaration that she had previously issued indefinitely, thereby rendering the building exempt from meeting certification requirements under the Building Act. She has repeatedly claimed the building is “safe”, despite no certifier signing off on it.

It is unclear whether Mr Riches’s TIO Stadium investigation will continue on its own or be rolled into the new joint investigation with the Ombudsman concerning the other sites.

Mr Riches asked for “any person, particularly those who work in building, certification and building insurance industries, who might have information relevant to this investigation” to contact the Office of the ICAC at icac.nt@icac.nt.gov.au.