The federal government has unreasonably delayed its decision on a Section 10 application regarding the Murujuga Cultural Landscape and will most likely have to pay the legal costs of the court action taken to expedite the decision, the federal court has ruled.

Justice Angus Stewart's decision on Monday related to an application from Mardathoonera woman Raelene Cooper and Kuruma Mardathoonera woman Josie Alec lodged on February 9, 2022.

Ms Cooper and Ms Alec applied in writing to the federal Minister for the Environment and Water for a declaration pursuant to Section 10 of the Aboriginal and Torres Strait Islander Heritage Protection Act seeking, in the words of Justice Stewart, "the protection of Murujuga from injury and desecration, primarily arising from existing and future natural gas extraction by Woodside Energy Group Ltd, a proposed urea plant development by Perdaman Chemicals and Fertilisers Pty Ltd, and existing and future ammonia and hydrogen production by Yara Australia Pty Ltd and related companies".

The area is home to the world's greatest collection of ancient rock art and was recently included in UNESCO's World Heritage list.

In a summary his findings, Justice Stewart noted "more than three and a half years later, the Minister has not yet determined Ms Cooper's s 10 application".

"On account of recent developments, (Ms Cooper) now seeks an order that the decision be made by 12 September 2025," he said.

"There is a positive duty under the relevant provision for the Minister to make a decision, and to do so within a reasonable time. The delay in this case is unreasonable in the legal sense, and it has not been adequately explained."

Justice Stewart said his conclusions are "not based on criticisms of the individuals in the Department of Climate Change, Energy, the Environment and Water directed at showing that they were too slow, or took steps that another person might consider were unnecessary".

"The process as a whole was not progressed at the pace that the standard of reasonableness in the relevant context and in all the circumstances required; long periods of relative inactivity with little to no progress occurred," he said.

"The point is that more than three and a half years for a decision on the s 10 application is, on the face of it, unreasonably long."

Justice Stewart found that the Minister had not adequately explained why the decision had taken so long.

"Setting out the various steps that were taken merely shows what has been done; it does not explain why those particular steps took so long, let alone why the whole process has taken so long," he said in his summary.

"There is no adequate explanation for the delay. It is not said that there was some extraordinary or unforeseen event that delayed matters."

However, Justice Stewart found that given the likelihood the decision was likely to come soon, he saw "little utility in ordering the Minister to make a decision by a particular date", but noted: "I will give Ms Cooper the liberty to apply for further relief if the decision has not been made by 12 September 2025."

The federal court judge also said the federal government should cover Ms Cooper's legal costs.

"Given the finding of unreasonable delay, and because the fact of this proceeding has led to the Minister's decision now being imminent, my preliminary view is that the respondent should pay Ms Cooper's costs of the proceeding," Justice Stewart said.

"However, I cannot determine the question of costs until the Minister's decision has been made and I have received the parties' submissions on costs."

Ms Cooper said the long delay was "deeply regrettable".

"After three and a half years of waiting for this process, I am relieved that the Federal Court has found the delays have been unreasonable," she said.

"I am also relieved to hear that the Department has finally recommended that the Minister makes a Section 10 Declaration for protection of Murujuga."

National Indigenous Times has contacted federal environment minister Murray Watt for comment.