"I am still trying to find out what happened," CEO Allan McGill said.

It has been almost three months since a fire erupted over 300 metres of old tyres piled high near the speedway track causing toxic smoke to fill the sky in Katherine's south.

The Katherine Fire Brigade worked quickly to manage the raging flames and dirt was piled on to extinguish the fire.

The former long-serving Katherine Town clerk was asked by an elected member to provide an update on the clean up, last night at the monthly Ordinary Meeting of Council.

Despite the tyres still smoldering beneath the soil, Mr McGill said the council is liaising with the NT EPA daily to ensure they are satisfied with the response.

"We plan to treat all contaminated material as soon as the fire is out," he said.

"Under the direction of consultants we will pull apart the 300 metres and get rid of the residual tyre material."

He said the contaminated soil would have to be addressed and the tyres completely removed.

"Our staff are down there every day liasing with the EPA making sure they are satisfied with our response," he said.

On behalf of the NT Environment Protection Authority, officers from the Department of Environment and Natural Resources are carrying out an investigation into the circumstances which led to the fire.

Thousands of old tyres had been stored by the council on vacant land between the showgrounds and speedway track.

Council has said it created the second tyre dump because it considered the fire risks were greater at the rubbish tip, where there was a further 450 tonnes of tyres.

But listed as a waste, tyres must be managed in accordance with the Waste Management and Pollution Control Act 1998 and its Regulations, a spokesman from the EPA said.

At last night's meeting, Alderman Jon Raynor implied the fire, which forced the relocation of free Territory Day events, was purposely ignited.

"It would have had to have help, it takes a lot of heat to get a fire to burn.

"It would have had to have an accelerant."

In discussion with fire fighters on the day of the blaze, Alderman Peter Gazey said he had been told there was an adequate fire break.

Despite many residents condemning the council's decision to dump the old tyres Alderman Elizabeth Clark said the tyres were deposited "with the best intentions".

"We were not storing them, we were trialing them for a fence," she said.

"At the time we thought it was a good idea, hindsight is a wonderful thing."

The Environment Protection Authority has said it is working with Katherine Town Council to ensure the tyres are dealt with properly.

"We are in regular contact with KTC to help them identify their issues and the expertise required to undertake the clean-up properly and are satisfied with the progress made thus far," a spokesman said last month.

The spokesman said the investigation was ongoing and he could not release details on possible outcomes or timelines.

The EPA has in the past said tyres can only be stored in a licenced location and the unsecured area at the rear of the showgrounds appears to breach those requirements.

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