Instead, Dr Andrew Lavender said he was confident smoking was to blame for the cancer.

“The numbers do not raise any concerns because it is certainly correlated with the incidences of smoking,” he said.

“We also know that smoking is much more common among indigenous populations ... and also the prison population.”

However the Port Augusta City Council and local MP Dan van Holst Pellekaan are yet to be convinced.They said they do not know where the health department got figures that reveal more Port Augusta residents smoke more than 25 per cent more than the state average.

Dan van Holst Pellekaan said he had been told the minister got the information from “a confidential source”, and has been unsuccessfully lobbying for access to the data.

“We are finding it extremely difficult to find smoking statistics specifically for Port Augusta,” he said.

“We’ve been in touch with the Cancer Council, we’ve been in touch with the department ... What’s confidential about smoking statistics?

“While I’m concerned that the minister won’t divulge the source, I do actually hope that he’s right. The most important thing for me is finding out why there is double the number of lung cancer rates in Port Augusta.”

This week Dr Lavender said country residents were actually much less likely to be at risk of lung cancer as a result of their contact with small particles in the air.

“While there is the power station the reality is exposure from particulate matters from motor cars is much more likely in the city,” he said.

In February the Port Augusta City Council wrote to state Heath Minister, John Hill, asking for an “analysis” of the figures on smoking in the city but is yet to receive a reply.

Port Augusta Mayor Joy Baluch said she wanted to know when and how the data which showed Port Augusta residents smoke much more than they state average was recorded.

“I think it’s appalling the way that they are ignoring us,” she said.