The potential billion dollar lease of NSW forestry assets has been delayed by the bushfire crisis, putting the government's major privatisation plan of 2020 at risk.

The state government commissioned an investigation into the sale of Forestry Corp’s extensive softwood plantations last year, but the devastating bushfires have destroyed almost 50,000 hectares, or 20 per cent of the asset.

A forest fire tears through a pine plantation between Tooma and Tumbarumba in southern NSW. Credit:Eddie Jim

While the report was expected to return in the first quarter of 2020, the Herald understands the bushfires have pushed that back until at least the middle of the year.

A spokesman for Treasurer Dominic Perrottet said the state would only go ahead with the deal, which was estimated to be worth about $1 billion, if it is "deemed to be in the best interests of the people of NSW,” he said.