• Mike Jeffries, the former CEO of Abercrombie & Fitch, likely has dementia, his lawyers say.
• Jeffries stands accused in an international sex-trafficking case.
• The illness means Jeffries won't be able to contribute to his own defense, his lawyers say.

Ex-Abercrombie & Fitch CEO Mike Jeffries likely has dementia and possible Alzheimer's disease, casting doubt on his ability to stand trial in a sex-trafficking case, his lawyers have said.

According to court papers filed Monday and seen by Business Insider, a neuropsychologist has assessed that "the combination of Mr. Jeffries' cognitive impairments" means that he would be unable to contribute to his own defense.

Jeffries, 80, along with his partner Matthew Smith and a third man, were arrested in October on federal sex-trafficking charges.

Earlier this month, lawyers for Jeffries filed a motion to determine his competency to stand trial.

The neuropsychologist found "a significant neurological deficit" after examining him in October last year and said her "initial diagnostic impressions" were consistent with dementia, the latest filing states.

Follow-up tests this year gave further "diagnostic impressions" of dementia and "probable" late-onset Alzheimer's, it says.

A diagnostic impression is a preliminary assessment of a patient rather than a final diagnosis.

"The Michael Jeffries who presented himself did not even come close to resembling a Master's degree-educated individual," the filing said.

The issues include "impaired memory, diminished attention, processing speed slowness, and ease of confusion," it continued.

The doctor has deemed his disease to be "irreversible" and said it will worsen over time, the filing said.

A so-called competency hearing has been scheduled for June next year, the BBC reported.

Jeffries, who left Abercrombie & Fitch in 2014, has pleaded not guilty to the sex trafficking charges, as have Smith and the third accused man.

Prosecutors say that they ran an international sex trafficking and prostitution business, coercing vulnerable men connected to the company into taking part in "sex events."

Between about 2008 to 2015, the accused men used the "so-called casting couch system" in their scheme, Breon Peace, the US attorney for the Eastern District of New York, alleged in a news conference announcing the charges in October.

The indictment states that the men used Jeffries' power and wealth "to run a business that was dedicated to fulfilling their sexual desires and ensuring that their international sex trafficking and prostitution business was kept secret, thereby maintaining Jeffries' powerful reputation."

His arrest came after a high-profile BBC investigation cited a number of men who said they were exploited or abused as part of the events Jeffries is accused of.

Jeffries was hired as CEO in 1990, ushering in a period in which the brand relied heavily on sex appeal to sell its preppy outfits. Huge popularity came alongside a 2003 class-action lawsuit that alleged racialized and looks-based discrimination against staff and prospective employees, which was settled in 2004 without admission of wrongdoing.