Another pop star is coming forward to criticize Dr. Luke, and this time it's original "American Idol" winner Kelly Clarkson.

While Dr. Luke (whose real name is Lukasz Gottwald) has been the focus of allegations of sexual assault and abuse by Kesha, Clarkson kept her opinions of him restricted to his professional behavior.

"A lot of artists that have worked with him don't work with him anymore for pretty good, solid reasons," Clarkson said during a radio interview on Australia's The Kyle & Jackie O Show. "He's not a good person to me. We've clashed. I can't really say anything other than that."

Except apparently she could: "Unfortunately, that poor of character -- I mean so many artists don't like you, don't like working with you, that's not normal," she said. "He's a talented dude, but he just lied a lot. I've run into a couple really bad situations. Musically, it's been really hard for me because he will just lie to people and it makes the artist look bad. And he's kind of difficult to work with, he's kind of demeaning."

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Clarkson has not collaborated with Dr. Luke in years, but he did work with her on her early hits "Since U Been Gone" and "My Life Would Suck Without You."

"Even the last time I worked with him, I only worked with him because literally I got blackmailed by my label," Clarkson said. "They were like, 'We will not put your album out if you don't do this.'"

While Clarkson was quick to clarify that she had never been in Kesha's "particular situation" with the producer, she did say, "I've heard a lot of girls have had similar situations. ... If it's true, I can't imagine working with somebody like that."