An acclaimed British crocodile expert has pleaded guilty to charges relating to beastiality and accessing child abuse material, the BBC has reported.

Australia’s Northern Territory Supreme Court heard allegations from prosecutors describing how Adam Britton, a 51-year-old zoologist, filmed himself torturing dozens of dogs before sharing videos of the incidents online under pseudonyms. They said he abused the animals in a shipping container on his property, which he called a “torture room.”

Prosecutors told the court Britton had a “sadistic sexual interest” in animals dating back to at least 2014, and that in the 18 months leading up to his arrest, he had abused 42 dogs, most of which died.

According to prosecutors, Britton would use an online marketplace platform to find people who needed to give their pets away because of work or travel commitments, and would offer to take the animals he would later abuse. One of the videos Britton shared was eventually passed on to authorities who arrested him, according to the BBC.

He also pleaded guilty four counts of accessing and transmitting child abuse material.

The details of the allegations were so disturbing that the judge took the rare step of excusing security officers and junior court officials from the room as some of the evidence was presented. Chief Justice Michael Grant said he was concerned hearing the facts of the case could cause “nervous shock,” the BBC reported. Most media outlets covering the case also chose to omit the most graphic details. 

“These facts contain material that can only be described as grotesque and perverse acts of cruelty which is confronting and distressing and which in my assessment have the potential to cause nervous shock,” the judge said.  

Britton was born and raised in the U.K. before moving to Australia more than 20 years ago. He built an international reputation through his work in crocodile conservation, even working alongside Sir David Attenborough on a docuseries.

Britton will return to court for sentencing in December.