Who knew they disqualified you from Fox's new reality show Married by America for already being married?

Denise L., a "suitor" on the reality show turns out to be separated -- but not yet divorced -- from her husband, thus breaking the show's rules of eligibility.

Entertainment Tonight broke the story last night.

ET segment producer Jane Cantillon, who confirmed the story, said that the day after the show debuted on Fox, a woman named Karen called a San Diego radio station claiming to be Denise L.'s sister-in-law.

"She said, 'Hey, I was watching Married by America and a funny thing -- Denise L. is not single. She's married to my brother -- and, by the way, those are fake boobs,'" Cantillon quoted Karen as saying.

"The radio station called me and I managed to finally confirm the story at Fox," Cantillon said. "They had no idea but they're grateful that we brought it to their attention."

Fox says the matter will be dealt with on Monday's Married by America.

"We will not discuss the personal lives of show participants -- however, it is against the rules to have participated in the show if you are or have ever been married," said a Fox spokesman.

"It was not known to the producers that this participant was married, and the situation will be dealt with on Monday's episode."

Cantillon said Denise L. is sequestered and has no idea that everyone now knows she's married.

In the show, five singles are searching for a potential mate from a group of "suitors" -- with America voting by phone on who should end up together.

Married By America, which premiered last Monday night, snared roughly 8 million viewers -- a far cry from the 20 million viewers who had tuned into Fox's Joe Millionaire.