A writ is expected to be filed in the High Court on Wednesday alleging the involvement of the secretive Exclusive Brethren in a variety of crimes, including fraud and kidnapping.
Three sisters, from India, who say they are on the run from the religious sect, allege they can link it to numerous crimes.
The women also allege the Exclusive Brethren is involved in money laundering, immigration fraud in New Zealand and bribery of police and members of the judiciary in India.
"We've got 3,000 pages of evidence ... and now we're going to expose this whole thing," one of the sisters told reporters in Canberra.
They said they feared for their lives and did not wish to be identified until after the legal action is taken.
They say they will file a "writ of mandamus" in Canberra.
