In official documents released under freedom of information laws, the Department of Territory and Municipal Services (TAMS) has conceded the official number of 1154 animals destroyed in the conservation cull in May and June last year did not include 407 "in pouch young".

The cull claimed 658 female and 496 male kangaroos in six nature reserves around the capital, including "at-foot" joeys - those old enough to have left their mothers' pouches.

Animal Liberation ACT, which leads the annual protests against the cull, accused the government of "keeping quiet" the number of in-pouch young for fear of public backlash.

The cull saw nightly cat-and-mouse chases around the city between cull shooters and animal rights protesters. The government was accused of deliberate animal cruelty and activists of having destroyed predator-proof fences, endangering important conservation projects.

According to the FOI documents, the non-reporting of in-pouch joey deaths is in keeping with licensing conditions for the annual shoot.

TAMS' head of parks and Conservation, Daniel Iglesias, said: ''Every single year we have gone public and we have said 'some of the females are likely to have pouch young', these animals are very good at reproducing,'' Mr Iglesias said.

''The important thing is that we are upfront about those pouch young and make sure we are humane about how we euthanise them. There's no conspiracy theory, we're quite happy to be open about the fact that in every culling year there will be females with pouch young.''

Mr Iglesias said the ACT was the only jurisdiction to limit its culling season, from March to July, in an effort to minimise the number of large pouch young present.

Animal Liberal ACT spokeswoman Carolyn Drew said, I think they keep quiet about it because for the general population, its a little more sensitive to hear about numbers of joeys being killed because most people, generally speaking, empathise with baby animals.

But it could also be partly because they (TAMS) dont really know the full number of the joeys they kill.

When it comes to in-pouch joeys it depends on the age, if its old enough to be thrown from the pouch or escape from the pouch. They might not know about those when they go through the bodies.

Ms Drew said she expected the full disclosure of the number of dead joeys to have a greater reaction overseas than locally.

A portion of the population will be upset about this news, but I still dont believe that Australians value the kangaroo as much as international people do, she said. But I know that that information will make the international stage and thats where you might hear a lot of the fuss and bother from.

The activist said she and her group were already beginning to organise their protests against the coming autumn and winter culling season.

Were already coming together to talk about the killing season, as I prefer to call it, Ms Drew said.