A depraved Seattle sex group whose members called themselves “The League of Extraordinary Gentlemen” was foiled for good this week when its ringleader was sent to prison.

Charles Peters, 49, was sentenced to three and a half years behind bars Thursday for his role in organizing the League — where affluent men paid for, and then rated, Korean prostitutes, The Seattle Times reported.

Peters – a clinical researcher who worked with terminally ill cancer patients at area hospitals – posted graphic “reviews” of the sex workers — known as “K girls” — on a private website called kgirlsdelight.com, under handles such as “PeterRabbit” and “TomCat007,” the paper reported.

He demanded that potential members meet him face-to-face before allowing them into the group, which included at least 32 people, according to court documents cited by the paper.

After meeting them, he provided “select” members with access to the site and exclusive “meet-and-greets” with the women at local bars and restaurants.

Peters was “a prolific sex buyer” himself, who spent more than $30,000 on prostitutes in one year, according to documents cited by The Seattle Times.

“[Peters] did as much as anyone to build and advance demand for prostitution in the Pacific Northwest,” prosecutors Gary Ernsdorff and Ben Gauen said in court documents.

But the group was busted in October after a woman living in a swanky apartment near Seattle told police she thought one of her neighbors may be involved in prostitution.

The group’s site, which went live in 2015, was visited by nearly 40,000 people per month. It was taken down in January 2016, according to the court papers.

Peters has been fired over the felony conviction, the paper reported.

“Mr. Peters’ life and career has been completely destroyed because (of) the state’s prosecution and subsequent convictions,” his attorney Jennifer Cannon-Unione wrote in a memo.

A total of 32 men from the group pleaded guilty to promoting prostitution. Peters was convicted on nine counts of second-degree promoting prostitution, according to the paper.

He is appealing the conviction.