Sydney  - Australia's consumer watchdog warned carmakers and other heavy polluters Thursday to stop falsely presenting themselves as environmental angels.

Australian Competition and Consumer Commission (ACCC) chief Graeme Samuel said he would make sure the law caught up with companies that "give an overall impression to consumers that their product is environmentally friendly when it isn't."

He named and shamed US-based General Motors for claiming the Saab cars it sold in Australia were environmentally friendly vehicles.

"Every Saab is green," the advertising ran. "With carbon emissions neutral across the entire Saab range."

Samuel said that planting 17 seedlings for each car sold wouldn't get anywhere near offsetting the carbon dioxide emissions over the life of the vehicle.

He also took to task V8 Supercars Australia for claiming that planting seedlings would negate the greenhouse gases from the car races it organized.

"When seedlings are first planted the amount of carbon that they absorb is likely to be very small," Samuel said. "It's not until the trees are fully grown that they can maximize carbon absorption."

Kate Norris, of consumer lobby group Choice, welcomed the ACCC action. "There are a growing number of consumers who want to buy greener and they are in need of accurate, relevant information about the environmental performance of products," she said. (dpa)