The Department of Environment and Resource Management is investigating a police officer who allegedly slaughtered 20 kangaroos on a Fraser Coast property at Booral in Queensland.

The officer told investigators the property owner gave him long-term permission to gun down the kangaroos. Some of the joeys were shot at point-blank range, as a result only one of three young kangaroos that the cop shot could be saved.

The carcasses of the roos were discovered in December by horse riders.

Australia's law considers the kangaroo a protected animal and killing the animal without a permit is an offense with a fine of up to $10,000 per kangaroo. To secure permit, landholders must show proof that the kangaroo population has caused damage to the property.

Residents of the area are not happy with the slaughter since roaming kangaroos has become a feature of the area. They recalled that a female roo regularly visits the back door of one home and recently brought along her young.

Australian Society for Kangaroo President Nikki Sutterby pointed out that illegal shooting of kangaroos often takes place around the country.

"It happens all the time and unfortunately because our government supports the commercial slaughter of kangaroos I think the public thinks it's open season," The Sydney Morning Herald quotes Ms Sutterby.

She stressed that the residents were not in conflict with the kangaroo population in the area, which numbers only about 20.