A Saudi prince is to be questioned again over allegations he drugged and assaulted a young model on a yacht in the Mediterranean three years ago.

Prince Alwaleed bin Talal, 56 – one of the world’s richest men with an estimated fortune of £12.3billion – is accused of assaulting the 20-year-old while in Ibiza in August 2008.

She said she woke up during the assault by a man she claims was Prince Alwaleed.

This week the prince issued a statement via his investment firm Kingdom Holding Company denying the accusations, branding them ‘completely and utterly false.’

He said he was not in Ibiza in August 2008 and has not visited the island for more than 10 years.

The statement also said the prince was unaware of the allegations until earlier this week and said he could have been mistakenly identified as the attacker after someone impersonated him.

The case was closed last year on the grounds of insufficient evidence but it has now been re-opened following an appeal.

The prince could now be called back to the island to provide a DNA sample. Court papers said forensic tests on the woman found evidence of assaulting activity and traces of a sedative.

Prince Alwaleed is a leading investor in both Citigroup and Rupert Murdoch’s News Corp. media empire, and held 26th place on this year’s Forbes list of the world’s richest people.

He is the nephew of King Abdullah of Saudi Arabia and bought London’s Savoy Hotel in 2005 for £250million.

The alleged victim claims she was lured on to the 384ft yacht Turama after her drink was spiked in a nightclub on the island.

The statement said: ‘The alleged encounter simply never happened. Indeed, the events could not have happened.

‘Neither His Royal Highness nor his lawyers were informed or aware of any complaint filed in Ibiza in 2008 or that the same complaint was dismissed in 2010.’

The alleged victim’s lawyer Javier Beloqui said if the prince was innocent he should just come to Spain to testify or provide a DNA sample for police to test against the DNA found in the woman.

She said: ‘If he is innocent, it is all over and if not, he will be charged . It is as simple as that.’

An official at the provincial court in Palma on the island of Mallorca said she could not confirm Spanish news reports that the investigating magistrate who was ordered to reopen the case has already subpoenaed the prince to come to Spain for questioning.

She spoke on condition of anonymity in line with court policy.