Eight men have been charged with committing hundreds of offences against a 13-year-old girl, including aggravated sexual penetration and sexual servitude.

Perth police said 503 charges have been laid by the Child Abuse Squad against the men, who are aged between 35 and 47. The girl's father is among those charged.

They said the girl's father arranged for the men to meet his daughter at various locations where the offences were committed.

Detective Superintendent Glenn Feeney said the charges included sexual penetration of a child under 13 years, indecently dealing with a child under 13 years, indecently recording a child under 13 years, distribution of child exploitation material, stupefying with intent to commit an indictable offence, and sexual servitude of a child.

He said police had seized computer storage devices containing a vast quantity of material, including 200,000 videos and 4 million images from one man alone.

"It's disgusting material. There's no words to describe it," Detective Superintendent Feeney said.

"The information retained from these electronic devices will clearly support the charges that have been proffered and also be used to continue to target other predators who are targeting children online."

He said the girl had been abused over a two-year period and was rescued from a house after information received from a member of the public.

"At the time of the offences alleged she was between the ages of 11 and 13," he said.

"She was rescued from this horrible situation she was in.

"She is safe, she is receiving the care that she requires and that will be an ongoing situation."

'The father was the common denominator'

Detective Superintendent Feeney said the girl's father was at the centre of the investigation.

"It will be alleged in the courts that each of the other offenders knew the father and it was facilitated by the father," he said.

"I believe the father was the common denominator here.

"But they're not part of any special group or sporting group."

Of the images and videos seized, about 149 were of the girl.

Some of the men charged had already appeared in court, Detective Superintendent Feeney said, including one who had pleaded guilty.

He said police were continuing to sift through the material.

"We're just continuing the investigation into any other possible offenders at the moment and it's ongoing," he said.

"As I said, we won't stop until we completely exhaust that investigation.

"Bear in mind we've seized so much material, electronic material which has been analysed by our computer crime people."

Detective Superintendent Feeney said members of the public were encouraged to report any information they had about this case or other offences to Crime Stoppers.

"I would like just to appeal to the members of the public. These type of offences are particularly horrifying," he said.

"In this case we rescued a 13-year-old child who may have been subject to further sexual offences."

The father has been charged with 228 offences, including 146 counts of aggravated indecent recording of a child aged under 13, 16 counts of sexual penetration of a child and six counts of sexual servitude.

Church pastor pleaded guilty to charges

Another of those charged, Dawid Volmer, 41, from Banksia Grove, also known as David Volmer, appeared in a Perth court earlier this month and pleaded guilty to 12 offences including indecent dealing and sexual penetration of a child.

Volmer, a pastor, is the former state manager of Prison Fellowship Western Australia.

Prison Fellowship Australia chairman Michael Wood said Volmer had resigned from his position as soon as the organisation was made aware of the charges against him.

Dawid Volmer, also known as David Volmer, pleaded guilty to 12 offences. ( Supplied )

"David had no involvement with Prison Fellowship programs involving children and his role at Prison Fellowship was not connected to the charges against him," Mr Wood said.

Ryan Trevor Clegg, 42, from the southern suburb of Attadale has been charged with 61 offences including indecent dealing with a child and sexual penetration of a child, 35-year-old Wanneroo man Nicholas Adam Beer faces 163 charges including three of aggravated sexual penetration and 148 of aggravated indecent recording of a child.

Others charged are Alfred John Impicciatore, 45, of Wembley, who is accused of four count of sexual penetration of a child, 47-year-old Mark Wesley Liggins from Coodanup, who is facing 10 charges including intent to procure a child for sexual activity and 41-year-old South Bunbury man Troy Phillip Milbourne, accused of 10 offences including three of sexually penetrating a child.

Benjamin Simon Clarke, 47, from Bedfordale faces 13 charges of indecent recording of a child and two of indecent dealing with a child.

The men are due to appear in various Perth courts in the next few weeks.