A federal judge on Tuesday delayed the trial of a Saudi Arabian couple accused of keeping an Indonesian woman as a virtual slave after prosecutors reported that a key witness was not available.

Homaidan Al-Turki and his wife, Sarah Khonaizan, face state and federal charges alleging they required the woman to cook, clean and provide child care in their home in suburban Aurora for little or no pay from 2000 to 2004.

Prosecutors also allege Al-Turki sexually abused the woman, and that she was sometimes loaned out to work for other families.

Labor officials say the couple owe the woman about $62,500 in wages.

Al-Turki and Khonaizan's trial on federal charges of forced labor, involuntary servitude and harboring an illegal immigrant was to start April 24. U.S. District Judge Walker Miller granted a delay because prosecutors reported a witness' failure to return to the United States from his home in Saudi Arabia. No new trial date was set.

Al-Turki and Khonaizan also face Colorado charges of kidnapping, false imprisonment and extortion, and Al-Turki faces state charges of sexual assault. Their state trial is scheduled for June 12.