Superior Court Judge Michael Trickey sentenced Charles Momah on Monday, nearly three months after a jury convicted him on two counts of rape and two counts of indecent liberties with patients. The standard sentencing range was 17 to 23 years.

Prosecutors said that Momah performed gynaecological exams without wearing gloves, sexually touched patients, probed them unnecessarily with a vaginal ultrasound wand and flirted with them inappropriately.

The obstetrician-gynaecologist prescribed addictive painkillers for no good medical reason, pressured patients into surgeries and double-billed insurance companies for procedures, prosecutors said.

"They will be sleeping with both eyes closed for the first time in so many years," said lawyer Harish Bharti, who represents dozens of women in civil lawsuits against Momah and his twin, who allegedly sometimes pretended to be the gynaecologist.

"My clients lived in fear under his reign of terror for years," he said.

Momah grew up in Nigeria and trained in Nigeria and Canada.

In 1993, after working in New York and Georgia, Momah moved to Washington state. The three clinics he operated are now closed. The state suspended his medical licence in 2003.

In 2000, a former patient told the King County sheriff's office that Momah had performed unnecessary surgery on her, deliberately got her addicted to painkillers, raped her five years earlier, and told her no one would believe her if she reported the rape because she was addicted to drugs.

Deputies investigated, but prosecutors decided there wasn't enough evidence to file charges.

Momah continued practicing until September 11 2003, when his licence was suspended after another patient reported being raped. By June 2004, 44 women had filed lawsuits against him.