Rio Tinto's relationship with an indigenous group in Kakadu National Park has taken ''two steps backward'' after a safety breach at the Ranger uranium mine. The Rio subsidiary that operates Ranger, Energy Resources of Australia, has confirmed that a vehicle used within the mine was taken out of controlled areas, sparking contamination fears among the nearby Mirrar people. Police are investigating the incident...ERA said the car...had been checked and was ''free of contamination''. But Justin O'Brien, who represents the Mirrar people, said it had caused great concern among the local community...ERA's relationship with the Mirrar people is crucial to its survival, given the company has agreed not to restart mining at Ranger without approval from the group.