Three women were allegedly sexually abused and filmed over a seven-year period, with the grim evidence stored on dozens of electronic devices.
A man, 39, will face court on Tuesday charged with more than 100 counts of related offences.
NSW Police arrested him in the Central Coast on Monday.
Detectives investigating an alleged domestic violence incident in December 2025 seized 120 drives from a home in Tumbi Umbi.
Police alleged they uncovered a large amount of covertly filmed sexual content.
A further investigation uncovered 2.5 million files, according to police.
The files contained sexual and physical abuse of three women, aged between 29 and 31, over seven years.
Police arrested the 39-year-old in Wellington and charged him with 109 counts of recording intimate image without consent, domestic violence.
He was charged with 57 counts of accessory to sexual intercourse without consent, and 12 counts of aggravated sex assault, deprive liberty.
Officers charged him with a further five counts of aggravated sex assault-offender in company of others.
He faces several further charges including administering poison and sexual assault by forced self-manipulation.