The raunchy sex lair leased by a Nxivm accountant was actually home to a high-ranking DOS sex slave, The Post has learned.

While the upstate New York hideaway was rented by bookkeeper Kathy Russell, it was secretly inhabited by “Grandmaster” Keith Raniere’s first sex slave Camila, according to multiple sources and court records.

Jurors seated on Raniere’s case were given a video tour of the Clifton Park condo Friday, which included fridge magnets spelling out lewd messages such as “I s—k big hard d—k!”

The abode also featured a tripod next to the bed, and a reverential photo of Raniere pinned to a bulletin board in the kitchen.

Though landlord Sheila Jelonek testified Russell paid annually for the pad in cash, fellow first-line DOS slave Lauren Salzman testified last month that Camila lived in the Knox Woods unit.

“[Camila] lived at 12 Wilton Court with her family for a period of time and then eventually moved to an apartment on Victory Way,” Salzman said on May 20 during her testimony as a cooperating witness against Raniere. She clarified the statement the next day, saying Camila lived at “120 Victory Way.”

Prosecutors allege Raniere began a sexual relationship with Camila when she was a minor, and possessed pornographic photos of her at age 15.

They also claim Camila was the first member of Raniere’s secret master-slave group, called DOS, in which women were branded with Raniere’s initials and ordered to sleep with him.

Russell’s attorney Justine Harris said her client simply rented the unit and had no additional knowledge regarding its use.

“Kathy Russell was deliberately kept in the dark about who was living at the Victory Way apartment, as well as what took place there,” Harris said in a statement.

Raniere’s sex trafficking trial continues Wednesday.

Russell pleaded guilty to visa fraud and is awaiting sentencing.