Scrutinizing the case of Xstrata's violation of the limits in the emission of lead, the Government has now announced that it will not prosecute the group anymore.

Environment Minister Kate Jones has clarified that the laboratory hired by Xstrata had wrongly interpreted the figures.

She had earlier indicated to impose a $2m fine on the company and also warned to shut down the mining unit. "Data showing elevated lead levels in the air monitoring at one of the six sites last week was the first time that data submitted by Xstrata to the department has shown any exceedence", she said.

However, after testing the air samples, it was found that the interpretations were wrong.

"I am satisfied there had been a reporting error and no breach. I'm advised that a change in Xstrata's laboratory service provider led to an over-calculation of their results", she said.