Heidi Montag‘s father was arrested Thursday for allegedly committing years of sexual abuse and incest with a 13-year-old girl.

According to Aspen, Colorado authorities, William Montag was arrested on an outstanding warrant on charges of child sexual abuse and aggravated incest. However, the charges have nothing to do with Heidi Montag or sister Holly.

Documents reportedly reveal that the sexual abuse of of the mystery girl began in 1993, when Heidi Montag was six, and continued until 1998. The girl alleges she was molested at least 50 times during the five-year time frame.

According to documents, as reported by TMZ, William Montag “groomed her with back rubs in her bedroom in the basement of their home.” The website reports that the abuse “escalated by attempting to insert a vibrator into her vagina. At age 16, he began performing oral sex. It then gets extremely graphic.”

.@heidimontag's father was arrested for the alleged sexual abuse + incest of a young girl -> http://t.co/AHFnrvwkej pic.twitter.com/U71a8YmHc8

— PopCrush (@PopCrush) January 31, 2015

Documents reportedly reveal that the last incident occurred in 1998, when William Montag allegedly “crawled into bed with her, tried to pull down her underwear and said, ‘I want to have sex with you.'”

The girl reportedly said, “Get the hell out of my room, no!” And he responded, “I thought that’s what you wanted. I thought you loved me the way I love you.”

Sources told TMZ that Heidi Montag and her husband Spencer Pratt know the accuser and say she “is determined to destroy the family.”

.@heidimontag's father has been arrested for doing a very, very bad thing: http://t.co/pa8Ky7jprL pic.twitter.com/aXDxyHyrth

— CELEBUZZ (@CELEBUZZ) January 31, 2015

TMZ says the couple, who claim the accuser has been stalking them at public appearances, refutes the claims and believe Heidi Montag’s father will be exonerated.

William Montag appeared on an episode of The Hills in 2009, when he walked Heidi Montag down the aisle as she wed Spencer Pratt.