Details have been revealed of the horrific sexual abuse of two young children at the hands of their "swinging" mother and stepfather, which was uncovered when a member of the public came across their "depraved" video recording.
WARNING: This story contains graphic content that some readers may find upsetting
The couple cannot be identified to protect the identity of the girl and boy, who were repeatedly abused between 2011 and 2015.
The girl was aged between five and nine, while her younger brother was between four and eight at the time of the attacks.
The District Court in Perth was told the stepfather, 49, and mother, 41, were part of the "swingers sex scene" and some of the incidents of abuse against the girl involved group sex sessions with as many as four adults.
Director of Public Prosecutions Amanda Forrester SC said the mother also worked as an escort and prostitute, and would sometimes have clients at the family home.
Ms Forrester also said the couple used drugs, including methylamphetamine, which they would sometimes give the children to smoke before abusing them.
A child's nightmare that became real
The court heard the abuse came to light after a member of the public found a camera memory card showing some of the acts at a short-term rental property and handed it to police.
There were two videos that ran between four and six minutes in which the adults could be heard talking to the girl, including telling her to relax, and the mother saying she is "definitely her mother's daughter".
In subsequent interviews with police, the girl disclosed further abuse, saying it would start with her being shown pornographic movies.
Ms Forrester said the girl remembered the first instance of abuse happened after she had a nightmare and went to her parents' bedroom.
Both parents pleaded guilty at an early stage to 17 charges arising from abuse that was recorded on the memory card, but they maintained for a long time they would defend dozens of other charges against them.
Abuse was 'depravity of the highest order'
A trial date was set for next year, at which the recording was going to be played to show the two had a "propensity" to commit offences of child sex abuse.
It was to be a judge alone trial after a ruling by the District Court Chief Judge Kevin Sleight, who said if the recording was shown to a jury there was risk it would "cause them psychosocial harm".
He described it as "very confronting, distressing and abhorrent" and noted that the responses of the victim to what was happening suggested she was "familiar" with it.
"It is capable of leaving the inference she was familiar with this type of sexual activity," he said.
"It is depravity of the highest order."
The mother eventually changed her plea to guilty to 40 charges against her, but the stepfather maintained his innocence and preparations were made for the girl to prerecord her evidence.
There was a special court hearing, called a "ground rules" hearing, to work out how best to accommodate the girl, including how best to speak to her, how to refer to the lawyers involved and what to do if she became fidgety or upset.
But eventually the stepfather pleaded guilty to about 40 charges.
He also admitted a charge of persistently engaging in sexual conduct with two other children, his two biological daughters, when they were aged between four and seven.
Maximum jail sentence sought
Ms Forrester said the State would be arguing for the maximum jail term to be imposed, saying the abuse fell "in the worst category".
"The gravity of the conduct is so extreme it's difficult to think of, in its totality, a worse case," she said.
The couple, who have been in jail since they were arrested last year, were again remanded in custody.
They are due to return to court in March, when their lawyers will provide submissions on their behalf and Judge Bruce Goteze may sentence them.
A third man, who was shown on the recording handed in to police, pleaded guilty to 17 charges and was sentenced to 21 years' jail, with an order he serve 19 years before he can be released.
An appeal against that term was heard earlier this week, with the Court of Appeal yet to hand down its decision.
The court heard the girl was only able to identify some of the other adults who took part in the abuse by their first names.
Ms Forrester said they had not been charged because of problems identifying them, but she said they remained suspects, and could and would be prosecuted if found.