Rabbit calicivirus disease seems to be spreading in Canterbury, and rabbit kills are increasing, says Canterbury Regional Council pest services manager Ian Lucas.

Council staff were reporting the disease spreading about two kilometres from release sites, and probably further in some areas, but this was not confirmed, he said.

Kill rates were starting to increase. "Some areas treated with (RCD-laced) carrots two weeks ago have kill rates up to 90 per cent already, and it is still killing rabbits," he said.

In the Mackenzie Country RCD was present over about 80 to 90 per cent of rabbit-prone areas, and kill rates were high, he said.

It was spreading down the Waitaki Valley from Omarama, and was in the Hakataramea Valley.

RCD was present in the higher areas of coastal South Canterbury, and there were suspected releases near Geraldine and on Rangitata Island.

Mr Lucas said that around Ashburton, on Banks Peninsula, and in the Kaikoura area farmers seemed to be waiting for a managed release. The only known release in the central plains area was in the Selwyn River.

In North Canterbury there had been widespread releases, sites including Lees Valley, the hill country west of Amberley, the Waipara River bed, the coastal hill country between the Waipara and Hurunui rivers, the southern end of the Lowry Range between Cheviot and Culverden, and the Waiau and Hanmer river beds.

Mr Lucas said the regional council did not have a role in monitoring or managing the disease yet. It was awaiting a legal opinion because of the risk of civil liability. That could come from farmers who did not want RCD on their properties. He believed those farmers would be more likely to take the council to court than other farmers.