Lori Loughlin and husband Mossimo Giannulli are looking to get the charges against them in the college admissions scandal case dropped.

Attorneys for the couple filed a motion to dismiss the case against their clients, claiming that prosecutors with the U.S. Attorney's office committed "extraordinary" misconduct.

According to the motion, and a subsequent memo supporting the dismissal motion, Louglin's lawyers allege that prosecutors acted inappropriately in regards to one of their main witnesses -- accused bribery scam ring-leader Rick Singer -- and that they tried to conceal exculpatory evidence.

"The extraordinary Government misconduct presented in this case threatens grave harm to Defendants and the integrity of this proceeding," the lawyers argue, according to court documents obtained by ET on Wednesday.

The documents claim that, in November 2018, "Singer called Loughlin and similarly used language to make it seem she knew the donations were bribes," after allegedly leading the couple to initially believe they were making legitimate donations.

"Loughlin answered '[u]m-hmm' and that she was 'confused,'" the documents argue. "The Government has repeatedly characterized Loughlin’s response as an admission of wrongdoing. But in a recorded call that Loughlin made to Singer three months later -- after her daughters’ high school received a grand jury subpoena for their academic records, and that was not directed by agents seeking to fabricate evidence -- Loughlin made clear she did not know the payments were bribes or have any idea that Singer had engaged in wrongdoing."

The documents claim that, during that recorded call, Loughlin made it clear that she wasn't aware of the possibly illicit nature of the payments.

"Yeah, no, no, I—I had questions about USC. I was like, ‘Well, maybe the way they got in you’re not supposed to get in like that, I don’t know, like can you,’ But Moss was like, ‘No, you can make a donation, it’s OK," Loughlin allegedly told Singer before asking, "But it’s all on the up and-up, right?"

Loughlin and Giannulli are accused of paying $500,000 in bribes to get their daughters, 20-year-old Olivia Jade and 21-year-old Isabella Rose, admitted to the University of Southern California as recruits for the crew team, though neither woman had ever participated in the sport. Both Giannulli and Loughlin have pleaded not guilty to all charges leveled against them, claiming their payments were donations to the school and not bribes.

ET confirmed back in February that the couple's trial date is set for October. The trial, which will take place at a federal courthouse in Boston, Massachusetts, is expected to last at least four weeks.

The trial date announcement comes one day after the couple's attorney filed documents requesting that the court "postpone the setting of any trial dates" until disputes and motions could be "briefed and decided."

This is when the couple's lawyers first argued that the U.S. Attorney's office had produced new information in discovery "that is not only exculpatory, but exonerating for Loughlin and Giannulli."

The docs further state that Rick Singer, the ringleader behind the college admissions scandal, had discussions with FBI investigators in which they "directed him" to make phone calls to his clients in order to get incriminating statements.

In response, the prosecution said that they "scrupulously adhered to its discovery obligations" in regard to providing Singer's notes to the defense, and are not "withholding any exculpatory evidence." They also called Loughlin and Giannulli's claims "hyperbolic and unsupported."

For more on the ongoing legal battle over the college admissions scandal, check out the video below.