Two animal activists have been spared jailtime after being found guilty of invading a farm in West Australia's south-west under the cover of darkness and stealing a calf.

Key points: The court heard of a "premeditated" and "brazen" plan hatched by animal rights activists to break into a farm and steal or "liberate" a baby calf

The court heard of a "premeditated" and "brazen" plan hatched by animal rights activists to break into a farm and steal or "liberate" a baby calf Warden received a 12-month suspended sentence while Swiebodzinski was fined $5,000

Warden received a 12-month suspended sentence while Swiebodzinski was fined $5,000 The owner of the farm targeted by the activists said the men's lack of remorse was disrespectful to the judicial system and mainstream society in general

James Warden, 25, and Arkadiusz Swiebodzinski, 26, had pleaded not guilty to charges of stealing and aggravated burglary at the White Rocks farm near Brunswick in October 2018.

Warden, who was also convicted of trespass at several WA piggeries and stealing a dead piglet, received a 12-month suspended sentence, while Swiebodzinski was fined $5,000.

The court heard details of a police investigation involving DNA testing, phone taps, and encrypted communication between the men.

Warden's role in the theft garnered him significant media exposure and notoriety, and made his name synonymous with veganism and animal activism in WA.

Thieves used encrypted message

In sentencing yesterday, the Perth Magistrates' Court heard of a premeditated plan by Warden, Swiebodzinski, and Mihaela Herceg to trespass on the WA farm under the cover of darkness on October 23, 2018, and steal a Friesian wagyu calf.

Herceg, who testified in the trial against the men, had previously pleaded guilty to the charges and been handed a one-year Intensive Supervision Order.

The court heard Herceg and Warden had entered the property to take the calf while Swiebodzinski acted as a lookout and laid blankets in the back of his car in preparation for their "liberated" passenger.

Police executed a search warrant inside Warden's Maylands home in February 2019 and a seized a phone belonging to him which contained messages, photos and videos made before, during and after the offence.

The court heard some of those images were later posted to social media.

James Warden also pleaded guilty to several other charges of trespass and one charge of stealing a dead piglet from a Pinjarra piggery. ( Source: Facebook/Direct Action Everywhere )

Messages and calls made by Warden via encrypted phone applications were presented as evidence in the case.

In an encrypted message sent soon after the theft, Warden said he had carried the calf "two kilometres through fences and 4-foot grass" and added "it's safe now".

Messages also showed Warden had later sought advice on the legal implications of "liberating a calf".

The court heard a "practice lockpicking kit" was also found at Warden's home.

Police subsequently searched Swiebodzinski's residence in East Perth in April 2019 and located the car he used to transport the calf from the farm in Brunswick to Greener Pastures Sanctuary in Waroona.

Prosecutor Sean Dworcan told the court there was no evidence to suggest the calf had poor health, aside from "diarrhoea", at the time of theft.

Police located the $300 calf, named Theodore by the activists, at the sanctuary five months after the theft and returned it to its owner.

Warden and Swiebodzinski showed little remorse as they fronted Perth Magistrates' Court. ( ABC News: Jon Sambell )

Investigators used DNA testing to confirm the calf was sired by a bull residing on the targeted farm owned by WS Partridge & Sons.

Defence lawyer Marilyn Loveday said that both men were merely accomplices to Herceg and not principle offenders.

"[Warden] was the muscle," she said in her closing submission to the court.

Ms Loveday said Swiebodzinski drove Warden and Herceg to and from the property but never entered himself and was not acting as a lookout.

Magistrate Dianne Scaddan disregarded those comments and said all three activists had acted with "a common purpose" to commit a crime.

'Brazen' and 'remorseless'

In his closing submission to the court, Mr Dworcan said crimes of this nature affected "the livelihoods of farmers".

He said the activists also created a biosecurity threat by entering the property, and the calf had to be temporarily quarantined once it was returned to the farm.

"A message does need to be sent to the community," Mr Dworcan said.

In her closing submission, Ms Loveday said the two men were not "troublemakers" and were simply youths with a passion for protecting animals.

"Of course, they went a step too far," she said.

"They're young and they haven't learnt yet that you can never win."

In her sentencing statement, Magistrate Scaddan said the crime was carried out "late at night" and designed with a "degree of subterfuge".

She said the line between animal activism and criminality had been crossed.

The magistrate noted the absence of remorse shown by Warden and Swiebodzinski and said her sentencing must act as a general deterrent for similar crimes in future.

Magistrate Scaddan said punishment must act as a personal deterrent for Warden in particular, who had also pleaded guilty to several other charges of trespass and one charge of stealing.

Digital evidence seized by police incriminated Warden in a string of other trespass offences and the theft of a dead piglet from a Pinjarra piggery in September 2018.

The court heard the dead piglet was later used in animal rights protests and displayed in public on a "white sheet, surrounding by flowers".

Magistrate Scaddan also denied a request for a spent conviction for Swiebodzinski, who is a Polish national and permanent resident in Australia with no prior convictions.

Little remorse from activists

After the court was adjourned, Warden and Swiebodzinski fronted the media in front of Perth Magistrates' Court, flanked by fellow members of the Direct Action Everywhere group who were wearing blue shirts that read "Right to Rescue".

Fellow animal rights activists called for a "right to rescue" animals from farms. ( ABC Rural: Jon Daly )

Warden said he accepted and respected the outcome of the criminal trial but had little remorse for his actions.

"I don't have any objections to what the magistrate said whatsoever but is that going to have an impact on myself and how we deal with animal rights?" he asked.

"Yes, in terms of our operations, tactics and methods, but in terms of liberating animals — not at all."

Michael Partridge is concerned the punishment will not be enough to deter others from similar crimes. ( ABC Rural: Jon Daly )

Swiebodzinski said the event marked the beginning of Australia getting a "right to rescue" animals.

Michael Partridge, the owner of the farm and the calf targeted by the activists, said he is concerned their sentence will not act as a deterrent.

"It's disappointing. We've been accused of being animal abusers," he said.

"They have fundamentally different beliefs, but don't break the law pushing your views."

Mr Partridge said the men's lack of remorse was disrespectful to the judicial system and mainstream society in general.