Regional Friends of Wildlife is adamant ACT taxpayers are spending $300,000 on annual culls which cause kangaroos to suffer for no other reason other than that the animals eat grass.

Documents the group sent to ACT ministers responsible for culling included a post-mortem by veterinarian Dr H. Ralph in June 2012, on a young male eastern grey kangaroo which it says endured at least three separate attacks during culling.

A Territory and Municipal Services spokeswoman said the claims could not be verified.

The Australian Society for Kangaroos took the dead animal from a burial pit at Goorooyarroo Nature Reserve.

Dr Ralph found the kangaroo was shot, than struck with a heavy blow and suffered a third wound which suggested it was stabbed in the neck.

The government's veterinarian said injuries could be consistent with a blow to the head and a puncture wound, but definitive advice could not be provided without an examination of the carcass.

''No other jurisdiction in Australia places as much emphasis on animal welfare in relation to kangaroo culling,'' the TAMS spokeswoman said.

Nearly half the kangaroos culled were examined in the field by a vet, who found 100 per cent compliance with a national code of practice for shooting kangaroos.

''The independent veterinarian reported that all kangaroo carcasses inspected had been killed with a single shot,'' the spokeswoman said.

''If an animal is not killed with the first shot to the head, the shooters, in compliance with the code of practice, ensure the animal is located and killed before any attempt is made to shoot another animal.

''Each year RSPCA inspectors are invited to attend the ACT government kangaroo conservation cull. Independent veterinarians have also been involved in auditing.''

Friends of Wildlife wants TAMS to remove from its website ''prejudicial and unsupported information on eastern grey kangaroos''.

Friends of Wildlife spokesman Phillip Machin said information sent to the government ministers included expert scientific testimony from the ACT Administrative Appeals Tribunal hearings in 2009 and last yer which exposed misleading and contradictory statements by the government's science advisers.

Mr Machin said kangaroo expert Dr Daniel Ramp had told the 2009 ACT Administrative Appeals Tribunal that research which attempted to show grazing impacts by measuring the reduction in plant biomass did not reflect a valid scientific approach.

Last year the tribunal approved licences for kangaroos to be culled at seven sites. But the tribunal ruled only 1244 kangaroos could be shot - 211 fewer than originally approved by the Conservator of Flora and Fauna.

The government says achieving eastern kangaroo grazing at an appropriate level is critical to Canberra's grassy ecosystem.

Government ecologists have been researching the relationship between kangaroo density and vegetation since 2009.

But because they are sampling a range of climatic conditions, they say the outcomes will take at least three to five years to fully assess.