(CNN) A Swedish doctor who authorities said imprisoned a woman for six days in a windowless cement bunker has been sentenced to 10 years in prison, a Stockholm district court said Tuesday.

Martin Peter Trenneborg, 38, was convicted of kidnapping after a trial in which prosecutors said he drugged the woman and then brought her to an underground bunker near his home in southern Sweden in September so that he could have a girlfriend.

Trenneborg also was charged with rape, but he was acquitted of that charge because of insufficient evidence, the court said. Authorities said Trenneborg admitted drugging the woman but denied raping her.

Rohypnol used

Stockholm chief prosecutor Peter Claeson said the woman's ordeal began in her apartment when the doctor served her chocolate-dipped strawberries that had been spiked with Rohypnol, a potent sedative known as a date-rape drug.

Once she was unconscious, the doctor put her in a wheelchair and wheeled her to his car. He drove her about six hours to his home outside the city of Kristianstad in southern Sweden, where he had built the bunker with its own plumbing and water supply, Claeson said.

Authorities said the woman was held for six days, and escaped only through an unlikely series of events. Once the man realized police were looking for the victim, he drove with her to a police station, armed with a gun, to tell officers that they were a couple, the prosecutor said.

But police asked to speak to the woman in private, and she told them of her ordeal, Claeson said.

During testimony, Trenneborg denied that any sexual activity had occurred while the woman was drugged, and said that he wanted the woman to be his girlfriend.

The doctor's lawyer, Mari Schaub, also told CNN last month that Trenneborg denied the rape allegation. While Trenneborg admitted building the bunker, he had no intention of sexually harming the woman, Schaub said.

"He is a man who was mentally depressed and when at the police station, complied with all the requests of the police," Schaub said.

"He is very much in regret of what he has done."

In court, Trenneborg attributed his actions to a mental disorder. A judge, however, decided that the disorder was not serious enough to mitigate the sentence, the court said.