A Saudi prince who murdered his servant at the culmination of a campaign of "sadistic" abuse was today jailed for life and lambasted by a judge for telling a "pack of lies" in an attempt to conceal his crimes.

Saud Abdulaziz bin Nasser al Saud, a grandson of the billionaire king of Saudi Arabia, was ordered to serve a minimum of 20 years for strangling and beating Bandar Abdulaziz to death at a five-star London hotel.

The prince bit the 32-year-old hard on both cheeks during the attack, which happened in their suite in February and was said to have had a sexual element.

He had been drinking champagne and cocktails when he began the ferocious beating after a Valentine's night out.

The Old Bailey had heard that the murder of Abdulaziz was the last act of a "deeply abusive" master-servant relationship in which the prince carried out frequent attacks on his aide "for his own personal gratification".

Saud initially believed he had diplomatic immunity, but his status as a Saudi royal could not save him from arrest and prosecution.

Sentencing him today, Mr Justice Bean said: "It is very unusual for a prince to be in the dock on a murder charge.

"No one in this country is above the law. It would be wrong for me to sentence you either more severely or more leniently because of your membership of the Saudi royal family."

During the trial, jurors were told that, by the early hours of 15 February, Abdulaziz was so worn down and injured he let Saud kill him without a fight.

The prince then spent hours on the phone to a contact in Saudi Arabia, trying to decide how to cover up his crime.

Bean said Saud had told a "pack of lies" to paramedics and police before finally admitting that he carried out the killing. He said he could not be sure whether Saud had intended to kill Abdulaziz, but added: "I think the most likely explanation is that you could not care less whether you killed him or not."

He told Saud he had treated his victim "as a human punchbag" and had never shown any regret. "If you had any remorse, you would have sought medical help immediately. But you were only concerned for yourself," he said.

The 34-year-old prince, who stood in the dock with his arms crossed, showed no emotion as the sentence was handed down.

He was found guilty of murder yesterday after the jury had deliberated for an hour and 35 minutes. He was also convicted of a second count of grievous bodily harm with intent, relating to a previous incident in a lift at the Landmark hotel, in Marylebone, London, where the men were staying.

Saud tried to conceal the true nature of his relationship with his servant, claiming they were "friends and equals", but a porter at the hotel said Abdulaziz was treated "like a slave".

The prince claimed he was heterosexual and had a girlfriend in Saudi Arabia, but he had booked appointments with at least two male escorts and one gay masseur and looked at hundreds of images of men on gay websites.

Photographs of Abdulaziz in "compromising" positions were found on his phone.

Saud denied killing his servant until shortly before the trial, when he admitted he had caused his death. Jurors rejected a claim by his barrister, John Kelsey-Fry QC, that Saud was guilty only of manslaughter.

His lawyers also failed in a last-ditch attempt to stop details of his encounters with male escorts being revealed during the trial. In a sign of the anxiety about his sexuality becoming public, the prince's legal team initially argued that the legal argument about the escorts should be held behind closed doors.

Kelsey-Fry said Saud had already faced abuse from Islamic fundamentalists being held alongside him in prison.

The court heard that homosexuality remains a capital offence in Saudi Arabia, and the country in which the acts take place has little relevance to prosecution under the country's sharia law.

If he ever returns to Saudi Arabia, Saud faces the possibility of execution. He could seek asylum in Britain when he is eventually released.