Police have uncovered more than 1200 mature cannabis plants with a street value of more than $3 million being grown at Bullaburra and Katoomba in the Blue Mountains.
On November 3, Blue Mountains Police executed three search warrants for "hydro houses" at Boronia Road and Railway Parade in Bullaburra and Cliff Drive in Katoomba.
Blue Mountains Police Detective Chief Inspector Scott McAlpine said three people were arrested leaving the Boronia Rd address - a Cabramatta woman, 42, a 44-year-old St Johns Park man and another man, 43, from Hammondville.
The Hammondville man was released pending further investigation, but the other two were charged with using electricity without authority, two counts of organising drug premises - first offence, and two counts of taking part in enhanced indoor cultivation of cannabis - commercial.
The Cabramatta woman and St Johns Park man were to appear at Penrith Local Court on Wednesday, November 4.
Det Chief Insp McAlpine said 1209 mature cannabis plants with a street value of more than $3 million and four vehicles, including a Range Rover Sport used in the commission of the offences, were seized by police.
Police inquiries are continuing.
Police urge members of the public to report any suspicious activity to Crime Stoppers where all information can be treated as confidential and can be anonymous.