Sentence slashed: 'Swinger' paedophile returning to NZ sooner than expected

Tracey Coulter was charged after police raided properties in Perth and regional WA. Photo / WA Police

A member of a "swingers" group who sexually abused a drugged 6-year-old girl will be returning to New Zealand sooner than expected after his prison sentence was slashed.

Tracey Coulter, 57, who lived in Perth at the time, abused the girl along with her mother, stepfather and other men during November 2012 and December 2014, AAP reports.

The man pleaded guilty to 18 offences and was sentenced in the West Australian District Court in March last year to 21 years in prison - one of the highest jail terms given to a paedophile in the state.

However, on Wednesday the West Australian District Court cut his sentence to 17 years.

Coulter now remains eligible to be considered for release on parole in January 2033 and will be deported back to New Zealand.

Initially, he had to serve 19 years before potential freedom, as he was eligible for release on parole in January 2037, ABC reports.

The Court of Appeal strongly disagreed the sentencing judge, AAP reports.

"While the offence does not fall within the 'worst category', it is nevertheless a very serious example of its type, bearing in mind the aggravating circumstances," the appeal judges said.

While the victim was abused, she was forced to watch pornographic films involving children and was given a pipe to smoke containing a stupefying substance.

The girl said in her victim impact statement that she sometimes felt guilty.

The girl's mother and stepfather, who cannot be named, have also pleaded guilty and will face a sentencing hearing next week.

Police launched Taskforce Mirzam after a member of the public discovered a device containing videos of the girl being sexually abused.