PROVIDENCE, R.I. (WPRI) – A federal investigation into a large-scale indoor marijuana growing operation out of a Providence mill building has expanded, including the arrest as a New York man identified by prosecutors as the “mastermind” of the conspiracy.

Samin Chang, 38, of New York, went before a federal judge Thursday afternoon on charges that he was the main player in a conspiracy that used a sophisticated indoor pot growing equipment inside a Branch Ave. mill building.

He was one of eight defendants arraigned following a superseding indictment.

Chang pleaded not guilty and was released on $200,000 bond by U.S. Magistrate Judge Patricia Sullivan. He has been ordered not contact the other defendants in the case and has to wear a GPS bracelet.

In court, Assistant U.S. Attorney William Ferland said Chang was a major financial backer of the conspiracy and visited Rhode Island frequently, giving money to co-defendant Richard Yang.

Ferland said the government seized surveillance cameras at the building housing the operation, which showed the activity and the defendants inside. He added the defendants moved roughly 30 pounds of marijuana to New York every month and they used an encryption app on their phones to communicate.

Chang was arrested Feb. 16 at JFK International Airport just as he was about to board a flight to Indonesia, Ferland said.

He added three defendants remain at large.

As Eyewitness News first reported, FBI agents along with the DEA raided the building at 725 Branch Ave. in August, seizing roughly 1,400 plants and charging three individuals, including a man identified by investigators as a New England mob associate.

At the time William Ricci, 69, of Providence, was charged with being a felon in possession of a firearm. According to court paperwork Ricci has agreed to plead guilty, the agreement with prosecutors will be heard by a federal judge next month.

Richard Yang, 35, was also arrested on charges of manufacturing more than 100 marijuana plants. He was later released to home confinement with electronic monitoring.

Named in the most recent indictment are Richard A. Yang, 36, Ilhwan Cha, 33, Ki T. Kwon, 32, Brian Lee, 28, Zipora Sardjuli, 55, Doddy Sambuaga, 45, and Irwan Anwar, 53, all of New York.

Lee, Sarjuli and Anwara are still at large and warrants have been issued for their arrests. Tim White( ) is the Target 12 investigative reporter for WPRI 12 and Fox Providence. Follow him on Twitter: @TimWhiteRI