Charges have been filed against additional men – including a director for Microsoft and a former Amazon director – following a large-scale sex trafficking operation in Bellevue, Washington. The men stand accused of promoting prostitution after investigators said they met with victims of sex trafficking at high-end apartments.

One of those charged is Sumit Virmani, the director of worldwide health for Microsoft.

Using the names "Appy" and "Jaytee," investigators said Virmani submitted over 70 reviews of prostitutes he had allegedly hired since April 2012, according to investigators.

When asked about Virmani's employment status, a spokeswoman for WE Worldwide -- Microsoft's PR company -- said she couldn't comment because it's a "law enforcement matter."

A spokesman later confirmed Virmani is no longer an employee at Microsoft.

Another man charged is Vivek Asthana. He was the director of software development at Amazon, and spearheaded the company's new FireTV.

Asthana used the name "Captain America" when he allegedly hired prostitutes at least 29 times through The Review Board and TheLeague.Net, according to court documents.

The tech directors are two of six local men charged late last month in King County Superior Court with promoting prostitution in the second degree – a felony charge.

All have been added to the 12 men and one woman arrested and charged when TheReviewBoard.net was shut down in January.

The sex workers operated out of high-end apartments in Bellevue and were the victims of sex trafficking, according to King County Prosecutor Dan Satterberg.

"These defendants, we allege, were absolutely devoted to the commercial sexual exploitation of vulnerable, powerless immigrant women," Satterberg said shortly after the initial arrests in January.

Police said the women were forced into prostitution to pay off debts to organized crime bosses in Asia. The women will not be charged with any crime. But now their alleged johns are.

That includes Mark Enfield, the owner of WesTek Marketing – an Eastside business that provides technology for public safety and the military. According to investigators, he used the alias "ItsMe" and has also been charged with promoting prostitution.

Benjamin Yu, a 36-year-old Boeing engineer who allegedly used the aliases "BrokenBoy08" and "Mike Chen," also was charged.

So was Dr. John Lui, a dentist from Bellevue, who used the name "PeteLeu" when booking prostitutes, according to investigators.

And Warren Watanabe, manager of a golf supply store in Federal Way, was allegedly known to TheReviewBoard as "Spencer Street."

All six are scheduled to be back in court next month. They all pleaded not guilty and are free on bail, which was set at $75,000 for each.

Boeing did not respond to requests for comment. Neither did Lui or a representative from WesTek. Watanabe's business and home phone numbers were disconnected.