THE tactics of radical animal activists have been revealed in parliament, ranging from stalking and threats over social media to posing as tradesmen to get access to government offices.
Australian Pork chief executive Margo Andrae gave evidence to politicians in a Senate estimates hearing.
The vegan vigilant harassment is so unrelenting, additionally police and security guards were on duty at Parliament House on Thursday in anticipation of Ms Andrae's appearance.
In one incident, an activist posed as a plumber to gain access to the Australian Pork offices, then hid in the toilets for hours.
In another, photos of the Australian Pork team celebrating international women's day was plastered across social media with the word "murderers".
"My favourite was 86 calls to my personal mobile in an hour," Ms Andrae said.
"There are threats on social media, there are personal threats against myself and my team. These people do not stop.
"They have come to my work, got in under false pretences, they have put it on social media and they denigrated my team -at what point is that even remotely OK?
"This behaviour is not acceptable and what they do is not okay, and it has to be called out or they will be no farmers in the future because they will not be game to walk out their front doors."
Ms Andrae said her staff were scared they would be followed home by the activists - who were not peaceful protesters - because they encouraged people to trespass.
"It is intimidation, it is bullying... they are criminals," she said.
"They are not everyday Australians just saying hi. They are criminals breaking the law. Yet they seem to keep being able to continue this."
Senator McDonald described the extreme activists groups as "thugs, bullies and terrorists".
"What I'm concerned about is that we are giving space and airtime and credence to people who are dangerous in their actions.
"They're extending to actually physically and mentally attacking people who are just doing their jobs," she said.
"I was really horrified to discover that this particular person has been threatened personally on social media, in their homes. Their children are frightened...How do we keep giving breath to these organisations?"
The evidence on activist tactics comes as footage aired on ABC of pigs in distress as they are stunned by carbon dioxide before slaughter, a legal and common place practise within the industry.
Ms Andrae's said the extreme activists represented "less than four percent of the population", and were not interested in animal welfare.
"There are very strong animal welfare groups like RSPCA - they are a really good body who meet us at the table, they talk to us and hold us to account to make sure we're doing things to the highest standard," Ms Andrae said.
"What these people do is not animal welfare, it's fundraising. That's all it is. It is fundraising and they've already had their charity status removed, so they go offshore [to seek donations]."
Agriculture Minister Murray Watt said expressed his "extreme concern and disgust" at the harassment experienced by Australian Pork staff.