Spain has reopened a probe into sexual assault allegations against a Saudi prince who is accused of raping a Spanish woman on a luxury yacht off the Mediterranean island of Ibiza.

Prince Alwaleed bin Talal, who is one of the world's richest people, is accused of raping a 20-year-old model in August 2008. In her complaint, the alleged victim said she was raped on the yacht after being drugged. But the case was dismissed last year for what the Ibiza judge called a lack of evidence.

But a Spanish provincial court, which has jurisdiction over Ibiza, Wednesday ordered the judge to resume the investigation and summon the prince to appear.

A summary of the court's order to reopen the case says medical tests conducted by Spain's National Institute of Toxicology and Forensic Science turned up traces of semen and a sleep-inducing chemical in her urine.

A spokeswoman for the prince's Kingdom Holding Company has called the allegations “completely and utterly false,” and says the encounter never happened.