LONDON (Reuters) - A Saudi prince was jailed for life in Britain Wednesday for beating and strangling his servant in the room they shared at a luxury London hotel after what prosecutors called a campaign of sadistic abuse.

Saud Abdulaziz bin Nasser al Saud (in white) is seen with his servant Bandar Abdulaziz in an elevator in London's Landmark hotel on January 22, 2010, on closed circuit television footage which was shown during a murder trial in London on October 5, 2010. REUTERS/Metropolitan Police/handout

Saud Abdulaziz bin Nasser al Saud, 34, was told he must serve a minimum term of 20 years in jail for murdering Bandar Abdulaziz, 32, also a Saudi, at the Landmark Hotel in February.

The prince, who told detectives he was a grandson of the Saudi king, had admitted manslaughter -- unintentional killing -- but denied murder. Standing in the dock with arms crossed, Saud showed no emotion as the sentence was handed down in London’s historic Old Bailey court.

Prosecutors described how the servant was bitten on both cheeks during a final assault by Saud. In previous attacks, the servant suffered “a series of heavy punches or blows to his head and face,” leaving his left eye closed and swollen, lips split and teeth chipped and broken, the Press Association reported.

There were horrific injuries to one of his ears and internal bruising and bleeding to the brain as well as severe injuries to the neck consistent with manual compression, prosecutors said.

They told the court that Saud tried to cover up the true nature of his relationship with his servant, saying they were friends and equals, but that a porter at the hotel said Abdulaziz was treated “like a slave.”

Prosecutors further said the two men were believed to have had some form of sexual relationship and that the physical abuse had a “sexual element.”

The prince testified he was heterosexual and had a girlfriend back home. Prosecutors said they found 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 Mr Abdulaziz in “compromising” positions were on Saud’s phone, prosecutors told the court.

When arrested, Saud at first believed he was protected by diplomatic immunity but his status as a Saudi royal was not sufficient, according to prosecutors.

Sentencing him, Judge David Bean said: “It is very unusual for a prince to be in the dock on a murder charge.

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