Two persons running a "residential brothel" in Denver were charged Monday morning by a grand jury. The duo was also accused of filing a false tax return after yielding profit from human trafficking.

They were indicted on eight counts including financial crimes, pimping and prostitution, money laundering, and violating the Colorado Organized Crime Control Act, according to a news release by Beth McCann, Denver District Attorney.

“This is the first time my office has used financial crime to indict alleged traffickers which has the elegance of sparing the trafficked women from testifying while also charging Gao and Zhang with a class two felony,” McCann said.

Michael Abeyta, who was living next door, said his wife called the human trafficking hotline after sensing something amiss as dozens of men in expensive vehicles thronged the house in all hours of the day.

Investigators have found “over 100 used condoms, a paper with Chinese characters that appeared to be a ledger, KY gel containers and used tissues,” when they scoured the litter outside the house. They also hinted at a sex-related website, backpage.com, that allegedly belonged to the duo, Fox 31 reported, citing the indictment.

Xiaoli Gao, 51, and Zhong Wei Zhang, 49, ran a flesh trade involving different massage parlors in Denver Metro area.

McCann said prosecuting the financial crimes will cover for the alleged victims, thereby relieving them from testifying. In fact, the chances of their re-victimization will also be curtailed by police, Paul Pazen, Denver police chief, said.

“Oftentimes, it is the victim of the sex traffic industry that was the one that was getting the handcuffs put on and getting prosecuted, and we want to make sure that…we’re holding the people that are exploiting vulnerable populations accountable,” Pazen added.

The accused will be arraigned on Feb. 10.

human trafficking
The shackled legs of suspected human traffickers are seen as they arrive for their trial at the criminal court in Bangkok, Thailand, on March 15, 2016. REUTERS