Conservationists say New South Wales Forests Minister Ian Macdonald should resign after a 24-year-old piece of evidence put logging on hold on the far south coast.

The South East Forest Rescue Group says logging in the Mumbulla State Forest, south of Bermagui, will devastate the last known colony of koalas in the region.

The group says Forests NSW ignored regulations and failed to conduct a proper investigation after a 24-year-old piece of evidence indicating a history of koala activity in the area was found 1.5 kilometres from the site last week.

The find has put the logging on hold for more than a week.

South East Forest Rescue Group spokeswoman Lisa Stone says Mr Macdonald was aware of the breach and ignored it.

“The level of inefficiency and blatant disregard for the rules seems to point to the fact that either the whole administration is corrupt or they just haven’t read their regulations,” she said.

The group is also pressuring the south coast regional manager of Forests NSW, Ian Barnes, to resign.

Mr Barnes says the appropriate surveys were carried out but the Environment Department is yet to determine if regulations have been breached.

“We endeavour as best we can to follow all those rules and regulations,” he said.

“In this particular case, there is one minor problem that is still yet to be resolved but we believe we may have overlooked an old koala record from 1986. Now, whether or not that will be a breach of our licence conditions will be up to the regulator.”

He says the logging does not pose a threat and is likely to resume tomorrow.

Forests NSW is logging the 100 hectares on the western side of the forest to feed the Eden saw mill. It says the site is far enough away from the koala colony.