WA Police say they've stumbled across a sickening "swingers" paedophile ring after a member of the public found a recording device containing video of child sex acts.

Officers are investigating videos depicting the alleged rapes of five children by 12 adults during organised group sex activities which were advertised online.

Twenty-three charges have already been laid against a husband and wife and their male friend who are accused of raping the 39-year-old woman's daughter.

The girl was just eight at the time, the abuse allegedly taking place between 2011 and 2016.

The trio have been charged with Sexual Penetration, Indecent Dealing and other offences.

A visibly disturbed Superintendent Sharon Leonhardt from the WA Police’s Sex Crimes Division told reporters that "it never ceases to amaze me what human beings do to one another - particularly when parents are involved". (9NEWS) (9NEWS)

Detectives are investigating more allegations of sexual abuse involving another nine adults - both male and female - against that girl and four other children.

Some of the children are related to each other.

Police believe at least some of the children were administered with prohibited drugs before they were sexually abused.

Taskforce Mirzam was launched last month following the discovery of the recording device's video allegedly showing adults, both male and a female, engaging in sexual acts with the eight-year-old girl.

Yesterday Taskforce officers raided six properties in Perth and regional WA and arrested three more people – they have since been released without charge.

On Monday, March 26, a search warrant was also executed at a home in South Australia, where various hard drives, lap tops, thumb drives and mobile phones were seized.

Detectives are working with the Australian Federal Police and Interpol to identify more suspects from electronic recordings, both nationally and internationally.

Further arrests are anticipated and dozens more charges expected to be laid.

Detectives believe there are people involved in the "swinging" or group sex scene who may have heard about, or been unwittingly exposed to, the paedophile ring's activities.

Anyone who has any knowledge of this child sexual abuse is urged to contact Crime Stoppers on 1800 333 000 or online .