Human trafficking charges against a Saudi princess accused of holding a Kenyan servant as a virtual prisoner in her California home were dismissed by a judge on Friday after prosecutors said they were unable to corroborate the allegations.

The 42-year-old princess, Meshael Alayban, smiled broadly as she left a Santa Ana courtroom after the judge lifted her $5 million bond, returned her passports, and ordered that an electronic monitoring device be removed.

Alayban had been charged with bringing her accuser to the US in May, confiscating her passport and paying her $220 a month to work 16 hours a day, seven days a week in circumstances Orange County's top prosecutor had likened to slavery.

But during a five-minute court proceeding that had been scheduled as an arraignment, District Attorney Tony Rackauckas told the judge, "The allegations cannot be corroborated, the people move to dismiss."

The judge agreed, and defense lawyer Paul Meyer said in court, "On behalf of the court and the nation of Saudi Arabia, we thank the DA for being a man of integrity."

Alayban, a wife of Saudi Prince Abdulrahman bin Nasser bin Abdulaziz al Saud, was arrested in July at her apartment in suburban Irvine, southeast of Los Angeles, and charged with human trafficking.

Authorities said the case came to light after the Kenyan woman, who is about 30 years old, escaped from the residence and flagged down a bus driver.

After Friday's hearing, District Attorney Rackauckas said the evidence from his investigation showed that "the victim here was not really a victim," adding that contrary to the accuser's account, she was free to come and go and received needed medical care.

"I think she believed she was a victim. I don't think she was lying to us. I think it was a misunderstanding and miscommunication," he said.

Defence lawyer Meyer said the accuser's claims were "based on lies," and he issued a statement calling the allegations a scam to gain permanent resident status in the United States. "This has been a nightmare for this family," Meyer said.

Defense lawyers had said all of the women working in Alayban's home were treated well.

"These women had cell phones, Internet, Facebook, and the family even bought cable in their native language for them," Meyer and lawyer Jennifer Keller said in a statement in July.

"They enjoyed full use of the spa, gym and pool, and were often dropped off to shop alone at neighborhood malls, all paid for by the family," the statement said.-Reuters