One of the nation’s biggest Republican donors and her company have been accused of engaging in discriminatory hiring practices. And the allegations are serious enough that state officials are now looking into the matter.

Regulators in Wisconsin say they have found probable cause to believe that Liz Uihlein and her company, industrial supply giant Uline, may have refused to hire an executive because she suffered from lupus, an autoimmune disease, according to internal state government records obtained by The Daily Beast. Uline denies the charges.

Uihlein is the company’s president. She and her husband, Uline CEO Richard Uihlein, are prolific Republican donors. Liz Uihlein was a major fundraiser for the Republican National Committee and the Donald Trump presidential campaign in 2016. With more than $20 million in 2018 midterm political spending between them, the Uihleins are currently the largest political donors in the nation, according to the Center for Responsive Politics.

The Uihleins have been particularly active this cycle in U.S. Senate races, where they have almost single handedly bankrolled independent political groups to boost their preferred candidates. Those candidates have included Alabama’s Roy Moore, Montana’s Matt Rosendale, West Virginia’s Patrick Morrisey, Wisconsin’s Kevin Nicholson, and Mississippi’s Chris McDaniel.

Discrimination allegations against the Uihleins’ company stem from a complaint filed in October. An applicant for a senior position at the company, whom The Daily Beast has declined to name due to privacy considerations, claims Liz Uihlein repeatedly brought up the applicant’s medical condition during a job interview last August, and indicated that she believed the condition would prevent the applicant from adequately carrying out her duties. Both Wisconsin and federal law prohibit employers from discriminating against applicants based on disabilities that would not affect their ability to perform the essential functions of a job.

Copies of the complaint and related documentation were obtained by The Daily Beast through an open records request. The documents indicate that an accompanying federal complaint has also been filed with the U.S. Equal Employment Opportunity Commission. The EEOC said it could not confirm or deny the existence of any such complaint.

The job applicant said in her complaint that, during her interview, Uihlein even inquired about her prescribed dosage of Prednisone, a steroid used to treat lupus, “which is a highly inappropriate line of conversation during a formal interview and none of her business.”

“I contend that the inappropriate line of questioning from Ms. Uihlein about my illness was what eliminated me from the candidate process,” the complaint alleges.

In a response to the complaint, Uline, the company, flatly denied that it had declined to hire the applicant due to her medical condition. Uihlein’s discussion of that condition, the company’s attorney wrote, “was one of compassion, not discrimination. Ms. Uihlein relayed her and her husband's own personal experiences with his autoimmune disease in an effort to empathize with Complainant.”

“Yes, Ms. Uihlein referenced her own husband's personal experiences as detailed in my initial complaint,” the applicant responded in a written retort, “but it wasn't to empathize with me over my disease but rather to further justify her concerns that she didn't believe someone with an autoimmune disease could do the job.”

Uline attributed its decision not to hire the applicant to her ostensible penchant for “job-hopping.” But the applicant pointed out that she had been employed by just three companies in the past 30 years, and left her previous job after less than two years only to be closer to her elderly parents.

The Equal Rights Division of Wisconsin’s Department of Workforce Development acknowledged the he-said-she-said nature of the allegations and Uline’s response, but found the applicant’s claims plausible enough to proceed with investigating the complaint.

In a letter dated February 8, the division said that Uline’s explanation “may be pretextual,” and that there is “probable cause to believe Uline may have violated the Wisconsin Fair Employment Law.” It proclaimed “sufficient information” to call an administrative hearing in the matter. No date for the hearing has been set, the division told The Daily Beast on Tuesday.

Uline, the company, did not respond to a request for comment on this story.

According to disability rights attorney Eve Hill, a partner at the firm Brown, Goldstein & Levy, the case against the company appears to have merit. “I would take this case,” she told The Daily Beast in an interview.

Parts of the dispute come down to a question of credibility, Hill explained, and Uline doesn’t appear to have the upper hand there. “It looks like the job-hopping allegation is pretextual, I don’t buy that at all,” she said. Uline also claims that the applicant “was looking for a more relaxed [work] environment,” which she denies, and on that dispute, Hill said, “since the employer has given a pretextual answer already, their credibility is diminished.”

The degree of sanctions that companies face if they are found to have violated equal employment laws can vary widely. For job applicants who were denied employment, companies can be forced to provide back pay, compensation for time that might have been spent in that position, emotional damages, punitive damages, and attorneys’ fees.

Beyond the immediate legal ramifications of the complaint, Hill said that the case illustrates the hurdles often faced by disabled job applicants, in particular due to the nature of this specific applicant’s condition.

“It’s an interesting case because lupus is generally an invisible disability,” Hill said. “This is exactly what people with disabilities are afraid of. Even though their disabilities don’t affect their work at all, people will assume that it does and not hire them.”