Three-time U.S. Olympian Suzy Favor Hamilton has been secretly working as a Las Vegas call girl for the past year, according to American investigative website The Smoking Gun.

In a lengthy article published Thursday, the website reported that Favor Hamilton, 44, admitted that she worked for an illegal escort agency under the alias Kelly Lundy.

“I’m owning up to what I did. I would not blame anybody except myself,” she told the website. “Everybody in this world makes mistakes. I made a huge mistake. Huge.”

After the story was published, the married mother took to Twitter to apologize and explain her actions.

“I was drawn to escorting in large part because it provided many coping mechanisms for me when I was going through a very challenging time with my marriage and my life,” she wrote.

“It provided an escape from a life that I was struggling in. It was a double life.”

Favor Hamilton is a seven-time U.S. champion runner, specializing in the 1,500 metres. She went to the Olympics in 1992, 1996 and 2000, and works as a real estate agent in Wisconsin.

In July, she described her history of depression to the Milwaukee Journal Sentinel. She told the newspaper that she suffered from postpartum depression after the birth of her daughter, Kylie, in 2005. She added that she still takes the antidepressant Zoloft.

The former middle-distance runner reportedly charged $600 an hour to accompanying men on “dates,” according to an online profile matching her alias.

Her services were provided by an illegal Las Vegas escort agency called Haley Heston’s Private Collection, according to The Smoking Gun.

Through the agency, Favor Hamilton also offered a “full GFE” (girlfriend experience) while clients could pay $6,000 to be with her for 24 hours, and an extra $300 for “a particular sex act,” according to The Smoking Gun. She also described herself as bisexual.

In an online review of her services described in the article, a supposed client wrote: “She is worth every penny. I will go bankrupt before I stop seeing her.”

The Smoking Gun reported that, as of early December, Favor Hamilton’s alias was ranked third-best “provider” in Las Vegas according to the escort rating website The Erotic Review.

Her husband, Mark Hamilton, was aware of her part-time gig, but “wasn’t supportive of this at all,” Favor Hamilton told The Smoking Gun.

She has appeared in a Nike commercial and works as a representative for Disney World. According to the Journal Sentinel, she gives about 60 motivational speeches per year, focusing on her mental health struggles.