Animal rights groups are furious a cruelty investigation into two Tasmanian abattoirs is still ongoing, eight months after it was launched.

In late 2016, Animal Liberation forwarded anonymous video footage taken at Gretna Meats and Tasmanian Quality Meats to the Department of Primary Industries, Parks, Water and Environment (DPIPWE).

In October, the group also made some of that footage public, releasing it to the media in protest.

It did the same thing in March with more footage amid concerns DPIPWE was not properly investigating the incidents.

Now Animal Liberation has released more video in a bid to push the issue further.

Chris Delforce, a farm animal campaigner for the group, described the vision as "horrific".

"We're seeing workers beating sheep, throwing them, kicking them repeatedly," he said.

The footage obtained by anonymous activists was filmed illegally but Mr Delforce said Animal Liberation believed it was something the public needed to see.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 2 minutes 48 seconds 2 m 48 s WARNING: GRAPHIC CONTENT: Tasmanian abattoir investigated after cruelty claims ( Peta Carlyon )

"Without activists, these practices wouldn't be known; it would just be going on day after day without anybody knowing anything or doing anything about it," he said.

Dr Andrew Nicholson, who has been a veterinarian in Tasmania for 43 years and before that a meatworks supervisor, said he was surprised no initial report, or recommendations, had yet been made.

"We can have as many regulations as we like but unless the regulations are seen to be enforced and overseen there is no point," he said.

Mr Nicholson said animal welfare was becoming a high priority for most people and authorities needed to properly respond to issues.

"The result of this whole episode is that it puts a cloud over the entire meat industry and other animal production industries," he said.

'More resources needed to enforce regulations'

Mr Nicholson said both the industry and the public would benefit from more resourcing and staffing within DPIPWE's animal welfare branch.

"I think it's a sad commentary on the resourcing of the departments responsible that we've come to rely on animal welfare organisations, some of them very activist, who feel obliged to enter premises illegally to gain this vision," he said.

"We have extremely comprehensive animal welfare legislation which covers all of these issues.

"The problem is you can have all the regulation in the world if you like, but if you're not resourced to enforce the regulations the regulations become meaningless."

'Winning complex cases take time'

RSPCA Tasmania's general manager Peter West agreed the investigation was taking a long time but said that was necessary due to the complexity of the cases.

"If these cases are to go to court and if there is to be a win in court then we need to take them seriously and the investigations need to be handled seriously as well," he said.

Mr West said the RSPCA had offered its support to the department, and would provide advice in line with a national push to improve abattoir practices.

"Some of those things include having CCTV cameras in the various abattoirs, as well as looking at what is best practice around the world," he said.

In a statement, a spokesman for DPIPWE confirmed both matters were still under active investigation and all aspects of the allegations were being thoroughly considered.

"The department is focused on ensuring the best outcomes are achieved in relation to all animal welfare matters," he said.