Leaked emails show firefighters expressed concerns about a potential "catastrophic" safety risk at Marrara Oval ahead of Saturday's AFL game in Darwin.

Thousands of people attended the game, which saw the Gold Coast Suns trounce the North Melbourne Kangaroos.

In the days leading up to the match, a health and safety officer within the NT Fire and Rescue Service (NTFRS) raised concerns about potentially inadequate water pressure and volumes at the venue, in correspondence leaked to the media.

The deputy chief fire officer (DCFO) subsequently approved an "enhanced response" for the AFL game, including the provision of a NTFRS bulk water carrier stationed near a booster outlet outside the stadium.

However, another firefighter noted that in the event of an emergency, the extra water would be depleted in 15 minutes or less, and therefore an additional water truck should be hired.

The request was knocked back because the DCFO said the contingencies already in place were "more than adequate".

In response, the firefighter said their team would adopt a "defensive strategy" focused on public evacuations in the event of a fire.

"Public and crew safety will be paramount, as it always is, however second only to that a defensive strategy will be adopted should a significant fire occur due to such limited water resources," the firefighter wrote to their supervisor.

NT government downplays safety concerns

Prior to the game, the ABC asked the NT Police Fire and Emergency Services (PFES) what was being done to ameliorate some of the concerns raised by firefighters.

In response, a government spokesperson said: "The Department of Infrastructure, Planning and Logistics (DIPL) continue to undertake significant works to ensure this public facility always has a high level of safety and reliability."

"This work includes repairs to stairs, replacing ageing roof structure, upgrades to the fire safety services, improved accessibility for the public including upgrades to the lifts and fire stairs," the spokesperson said.

The spokesperson said emergency management at the stadium was a matter for AFLNT, but AFLNT told the ABC that PFES was best placed to respond to questions.

While TIO Stadium hosts major AFL and NRL games in Darwin, it has done so without a legally required occupancy certificate since it was built in the 1990s.

Three months ago, NT Infrastructure Minister Eva Lawler issued a declaration making the stadium temporarily exempt from requiring the key safety certificate.

That decision prompted independent commissioner against corruption Michael Riches to launch an investigation.

"The investigation I have commenced follows matters that have been brought to my attention about the facility and its compliance with the Building Act 1993, together with correspondence and information that I have received over the last several weeks from members of government, and others," Mr Riches said in March.

At the time, Ms Lawler said the temporary exemption was designed to give a building certifier time to assess the facility and provide the required certificate.

She said the stadium was safe and the government was still working to secure certification.

"Territorians have been using and enjoying TIO Stadium [Marrara Stadium] for 30 years," she said.

"The absence of an occupancy permit is a longstanding issue. DIPL is working to rectify this."

Ms Lawler said the government would cooperate with any ICAC inquiry.