SAN FRANCISCO >> The case of a Northern California woman who said she was kidnapped for ransom only to have it called a hoax by local police took another bizarre twist Monday when federal prosecutors announced they charged a man with her abduction.

The allegations against Matthew Muller, of Orangevale, California, 38, were contained in an affidavit that was unsealed Monday. He was charged last month after he was arrested in South Lake Tahoe in a home-invasion robbery in the San Francisco Bay Area that had similarities to the kidnapping, the FBI said.

The case began when the woman’s boyfriend, Aaron Quinn, reported that kidnappers broke into the couple’s Vallejo home March 23, abducted her and demanded an $8,500 ransom.

Quinn’s lawyers have said he awoke to a bright light in his face, and two kidnappers bound and drugged him.

The 29-year-old woman turned up safe two days later in her hometown of Huntington Beach, where she says she was dropped off. She showed up just hours before the ransom was due.

The Associated Press is not naming the woman because she says she was a victim of sexual assault. The FBI says they found no evidence of nonconsensual sex.

After the woman reappeared, Vallejo police said at a news conference that the kidnapping was a hoax. Police have since declined to comment other than to say they continue to investigate. A call to the Vallejo department was not immediately returned Monday.

Attorneys for Quinn maintained the kidnapping was real.

FBI Special Agent Jason Walter said in the affidavit “recently discovered evidence” led him to conclude there was probable cause to believe Muller kidnapped the woman.

Investigators who arrested Muller in South Lake Tahoe found a laptop that resembled one Quinn had. A search of a stolen car that was connected to Muller turned up numerous other items — including a water pistol with a flashlight and laser pointer on it — that were shown in photos that were emailed to a newspaper by people claiming responsibility for the woman’s abduction, Walter said.

A cellphone in the car had one of the same photos.

Detectives also found a pair of goggles with a long blond hair in it, the same hair color as the victim’s. The goggles were similar to those the woman and Quinn said they were forced to wear during the kidnapping, Walter said.

The navigation system in the car connected to Muller turned up a Huntington Beach address.

Muller was in custody Monday in Alameda County, where the home-invasion robbery occurred.

People purporting to be the victim’s kidnappers also sent an email to Vallejo police demanding they apologize for calling the kidnapping a hoax and acknowledge they were wrong.