THE owners of Australia's biggest uranium mines paid a former undercover Victoria Police officer to infiltrate environment and Aboriginal groups in Melbourne.

The former police intelligence unit officer, known as Mehmet, was hired by North Ltd — before its takeover by Rio Tinto in late 2000 — and US nuclear and defence giant General Atomics to spy on Friends of the Earth, Jabiluka Action Group, Nuclear Free Australia, radio station 3CR and radical Melbourne bookstore Barricade Books.

Mehmet first infiltrated the Jabiluka Action Group and Friends of the Earth in 1998 as part of an undercover police operation. It is not known why police chose to infiltrate and monitor the groups, though both were involved in anti-uranium protests.

After leaving the police in late 1999 to set up his own security company, Universal Axiom, Mehmet retained his covert police persona as a Kurdish migrant concerned about indigenous and mining issues.

He was able to stay inside the groups and provide information to the mining companies about campaigns being planned against their respective uranium mining operations until his cover was blown in mid-2001, when Friends of the Earth received an anonymous phone call warning about Mehmet's true identity.

Deputy Police Commissioner Simon Overland told The Age it was a breach of the Police Regulations Act for an officer to use a covert identity after leaving the force or to use information gathered in the course of official duties for private gain.

"It's a criminal offence and we would take that very seriously. We have prosecuted people in the past and we will continue to do so when they do that," he said.

Mr Overland also acknowledged some covert operations by Victoria Police in the late 1990s were not as accountable as they should have been.

"It is pretty much a matter of public record that there were issues with the way activities in this area operated in the past," Mr Overland said. "But I do make the point that it is eight years ago … I want to make it very clear that that is not the way we do business now."

Friends of the Earth spokesman Cam Walker said there was no justification for police infiltration of the group in the late 1990s, especially as it was already holding regular meetings with the police intelligence unit at the time to discuss its campaigns.

Mr Walker said it was unethical for mining companies to pay the former undercover officer to continue to spy on groups opposed to uranium mining.

"It is inappropriate on so many levels. We are a membership-based community group," Mr Walker said. "We are no risk of violence against the police or the companies. We see this as a criminal act, particularly as the guy came to be here in the first place as a police officer."

Former North Ltd executives have confirmed the engagement of Mehmet's company, Universal Axiom, as well as two other corporate intelligence firms, British-owned Control Risks Group and a Melbourne firm headed by another former undercover Victoria Police officer.

"We were facing a very strong, active protest outside our Melbourne headquarters because of Jabiluka and we needed security advice to protect our staff," a former company executive said.

"We were also facing a takeover and we had to take steps to ensure the security of our internal information and boardroom discussions."

It is believed only a handful of North Ltd executives were aware of the engagement of Mehmet, who was first hired to assess the quality of information supplied by other private intelligence firms.

A spokesman for Rio Tinto, which acquired North Ltd in late 2000, said the company was not aware of North Ltd's engagement of security consultants.

"We hire security companies and consultants to support our operations worldwide," the Rio Tinto spokesman said. "However, the purpose of these contracts is solely for the protection of the group's assets and personnel, it is completely defensive. These services are not used for infiltration of competitors or anyone else."

US company General Atomics and its Australian subsidiary, Heathgate Resources, declined to answer questions about Mehmet, who also provided personal protection to visiting General Atomics executives.

A Heathgate spokeswoman said the company was privately owned and had a policy of not responding to media questions.