He spent a night in jail at the time and was released after posting a $300,000 (269,000 euros) bail.
Jane Robison, a spokeswoman for the Los Angeles district attorney`s office, said authorities had decided not to pursue the charge of forced oral copulation against the prince because of lack of evidence.
"There was insufficient evidence to file charges," Robison told AFP.
"That`s why we refered the case to the city attorney`s office so that they can review and decide whether to file misdemeanor charges."
Frank Mateljan, of the Los Angeles city attorney`s office, said the case was under review and it was unclear whether the prince would face any charges at all.
Police were called to the palatial mansion in Beverly Hills after a bleeding woman was heard screaming for help as she tried to scale the wall of the property.
She told police that the prince had sexually assaulted her. Four other people also claimed they were victimized by the prince but not all alleged sexual assault.
The prince left the mansion following the incident and it was unclear whether he was still in the United States.
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