The Greens want imports of illegally logged timber halted.

Green co-leader Russel Norman today released the party's forestry policy which he said aimed to protect New Zealand's timber industry from cheap, illegally logged rainforest timber.

Dr Norman said the Ministry of Agriculture and Forestry estimated the cost of overseas illegal logging to the local industry at $266 million a year.

"A ban on the sale and import of illegal timber and wood products, combined with certification of indigenous forest products and country-of-origin labelling will go a long way to protecting both our industry and workers -- and the irreplaceable rainforests of Papua New Guinea and Indonesia," he said.

He said New Zealand also needed to avoid introducing genetically engineered forests and said diversification into higher value species including hardwood natives was needed to reduce the need for toxic treatments.

The party said the emissions trading scheme added value to the forestry industry.