A group of 21 people accused of illegally growing and distributing marijuana in Colorado has been indicted in an alleged money-laundering scheme, county and federal officials said Thursday.

The group grew and distributed marijuana throughout the Denver metro area, with facilities to grow and stash the drugs across the state, authorities said in a news release.

Officials have seized about $1 million worth of marijuana proceeds, hundreds of pounds of the drug, and more than 10,000 marijuana plants, said District Attorney John Kellner, whose office covers several counties just south of Denver.

The 45-count indictment, the result of a year-long investigation, describes how defendants allegedly grew illegal marijuana and laundered money through Mexican drug trafficking organizations, social media applications, QR codes and illegal money brokers located in China.

The 21 people face numerous charges that include racketeering and conspiracy, drug cultivation and distribution, and money laundering, according to the Arapahoe County District Attorney’s office.

“The defendants in this case are alleged to have gone to great lengths to carry out their sophisticated money laundering conspiracy to fund illegal activity, and they will now face justice for their crimes,” Steven Cagen, special agent in charge with Homeland Security Investigations (HSI) Denver, said in a press release.

Sixteen Chinese citizens allegedly involved in the scheme have been arrested, and five others have outstanding arrest warrants, officials said.

Recreational marijuana is legal in Colorado. But companies must apply for marijuana business licenses to be a verified seller in the state.

Colorado’s recreational marijuana laws have made it easier for “groups like this to flourish,” Kellner said.

“When the discussion and the debate about legalizing marijuana in the state of Colorado was coming to a head, there were many people who said this was going to eradicate and end the black market — and that is incredibly far from the truth,” he added.

Agents from the U.S. Drug Enforcement Administration and Homeland Security Investigations participated in the investigation.