Animal activist and group spokeswoman Emma Haswell said that the group wanted to perform a spot inspection on the piggery because of concerns for the conditions under which the pigs were being kept.

"We'd all had foot baths, had our temperatures taken and were wearing bio-suits to ensure we posed no risk to the animals," she said.

"Animal Liberation NSW president Mark Pearson introduced himself to the farmer who refused to give his permission for a spot inspection, saying we should return in 24 hours.

"A lot of people don't realise the conditions these animals - considered by scientists to be as intelligent as a four-year-old child - live in.

"They spend much of their lives in steel and concrete crates the size of their bodies."

Tasmanian Island Pork Alliance coordinator Malcolm Cowan would not identify the farmer and said that only RSPCA or Primary Industries officials had the power to request spot inspections.

All Tasmanian piggeries operated within the industry code of practice, he said.

"The code is currently before the Animal Advisory Committee for review," Mr Cowan said.

"Pig farmers are subject to random audits from DPIW and RSPCA officers and there is a third party audited element in our quality assurance program."

But Ms Haswell said that the code of practice over-ruled the Animal Welfare Act which forbade the confining of animals without provision for exercise.

"The code of practice for the welfare of pigs was written by industry and the government and recommends keeping pigs, one of the world's most intelligent animals, in a crate 2m long and 60cm wide," she said.

"Changes being sought will make it even more difficult to prosecute pig farmers - (Primary Industries Minister) David Llewellyn has not yet implemented the new code and we're asking him not to."