A Swedish doctor has been charged with rape and kidnapping after he confessed to drugging a woman with sedative-laced strawberries and locking her up in a soundproof bunker where he had intended to keep her for years, prosecutors said Monday.

The 38-year-old man's defence lawyer described the case as an elaborate plot to find a girlfriend, which unraveled as he walked into a police station with the woman on Sept. 18 last year, allegedly to show police that she was fine.

"I haven't seen any case like this. I think it's unusual," prosecutor Peter Claeson told The Associated Press.

Defence lawyer Mari Schaub said her client has confessed to all allegations except rape, but wants the kidnapping charge reduced to a lower charge of deprivation of liberty.

Met victim once before abduction

According to the indictment, the defendant built what was meant to look like a machine shed next to his countryside home in southern Sweden. Inside it was a concrete "bunker" with double metal doors.

"The purpose of the building was to keep people incarcerated during an extended period of time without detection," the indictment said.

The doctor, whose name wasn't published in Sweden in line with privacy rules, allegedly made contact with the victim by phone and met her once before he abducted her in Stockholm on Sept. 12 after careful preparations.

The woman, whose age wasn't provided in the indictment, passed out after he gave her chocolate-coated strawberries laced with Rohypnol, also known as a "date-rape drug." Prosecutors say he had sex with her while she was unconscious, which his defence lawyer said he denies.

He then wheeled her to his car in a wheelchair and drove 530 kilometres (330 miles) to his home outside Knislinge, giving her drugs intravenously during the journey to keep her sedated. Prosecutors said he also brought two rubber masks "featuring an older man and older woman" to avoid being recognized.

Intended to have unprotected sex

When they arrived the next morning, the defendant locked the woman inside the bunker where she remained until Sept. 18, except for a few brief occasions when he led her in handcuffs to his home to take a shower, the indictment said.

He allegedly told the woman he intended to have unprotected sex with her and took blood samples and vaginal samples to check whether she had any diseases. He said he wanted to keep her there for years and that he planned to lock up other people, too, according to the indictment.

Prosecutors said the defendant's plot started falling apart when he returned to the woman's apartment on Sept. 17 to fetch some of her belongings. That's when he found out that police were searching for the woman and had changed the locks on her front door.

A 'very sad and depressed person'

He returned to his home, picked up the woman, and drove to a Stockholm police station the next day with the intent of picking up the new keys to her apartment and making her assure police that she was fine.

The police officers got suspicious and took the woman aside. She told them she had been kidnapped, and the defendant was arrested, the indictment said.

Defence lawyer Mari Schaub described her client as a "very sad and depressed person who wanted a partner" and said he deeply regrets what happened.

"He never meant to hurt anyone," Schaub said.

A psychiatric examination found the defendant mentally fit to stand trial, both the prosecutor and the defence lawyer said. The trial is expected to begin next week.