A probe was launched after a former employee of mine owner ERA Ltd raised allegations of environmental mismanagement at the Ranger uranium mine bordering Kakadu National Park in the tropical far north between 1996 and 1998.

"The report concludes that no evidence has been found that Energy Resources Australia has operated otherwise than in accordance with its authorisation and the Commonwealth's environmental requirements," Environment Minister David Kemp said.

ERA was criticised by Kemp's office April for failing to safeguard the environment in two incidents in 2002.

In these incidents, the government ruled that while the environment was not harmed during the mismanagement of a low-grade ore stockpile at the Ranger mine and the delayed reporting of uranium levels during January and February 2002, ERA needed to upgrade its system.

"BLANKET ASSURANCES"

ERA was "now committed" to achieving compliance with international standards of best practice, Kemp said.

The report covering 1996-1998, prepared by scientists from Commonwealth and Northern Territory agencies, makes recommendations for improvements in chemical monitoring and the assessment of water discharges, Kemp said.

Australian conservation foundation campaigner David Sweeney said the report was inconclusive over the extent of spills from the mine and superficial in some areas of investigation.

"We think the findings and the blanket assurances given by the minister are not justified," Sweeney said.

A spokesman for ERA said the company was satisfied that the report had failed to uncover any evidence that the company acted outside of authorised procedures over the period.

The former employee, Geoffrey Kyle, charged that contaminated spills at the mine were improperly reported by ERA.

However, Kemp said "many of the issues raised by Kyle were no longer relevant because of significant changes in staffing management of the mine in recent years."

ERA, a 64 percent-owned subsidiary of Anglo-Australian mining house Rio Tinto Plc/Ltd since 2000, has been targeted by environmental and indigenous peoples' groups opposed to uranium mining near the park.

Hearings for a Senate inquiry into uranium mining begins in the Northern Territory city of Darwin today.

ERA has already agreed never to mine a neighbouring uranium deposit called Ranger Two because it is considered a sacred site by the local Mirrar Aboriginal tribe. A third deposit in the township of Jabiluka is also unlikely to be mined given local opposition, Rio Tinto has said.