SAN FRANCISCO — A disbarred Harvard University-trained attorney was set to plead guilty in a kidnapping case in California that police initially dismissed as a hoax, the U.S. Attorney’s office said Wednesday.

Matthew Muller was expected to enter a new plea on Thursday, said Lauren Horwood, a spokeswoman for the office in Sacramento.

She did not provide further details, and no documents were immediately available laying out the terms of the plea change.

A call to Muller’s attorney, Thomas Johnson, was not immediately returned.

Johnson has said Muller suffers from bipolar disorder.

In a court filing Tuesday, prosecutors asked a judge to inquire during the change of plea hearing about Muller’s mental condition and medications to make sure he understands the proceedings and his rights.

Muller previously pleaded not guilty to a kidnapping charge that prosecutors say stemmed from his abduction of Denise Huskins from her Vallejo home in March 2015.

Huskins’ boyfriend, Aaron Quinn, reported that kidnappers broke into the couple’s home, abducted Huskins and demanded $8,500 in ransom money — a figure police have said they found small for what would have been an elaborate kidnapping.

Huskins turned up safe two days later in her hometown of Huntington Beach, where she says she was dropped off.

After Huskins reappeared, Vallejo police said the kidnapping was a hoax.

Huskins has filed a lawsuit accusing police of wrongly likening the case to the movie, “Gone Girl” and damaging the reputations of her and her boyfriend.

Attorneys for police have said investigators doubted Quinn’s account of the abduction and grew more skeptical when Huskins refused to reunite with her family soon after she reappeared.

Muller was admitted to practice law in California in 2011 and his state bar profile says he attended Harvard Law School.

He lost his law license last year over allegations that he took a $1,250 advance from a client then failed to file a green card application for the person’s son.