The Prince of Wales and the Foreign Secretary have paid tribute to Saudi Arabia's heir to the throne, who has died at the age of 85.
Crown Prince Sultan bin Abd Al Aziz died abroad in the early hours after an illness, according to national TV.
He was the half brother of the Saudi king, the kingdom's deputy prime minister and the minister of defence and aviation.
Foreign Secretary William Hague said he was sad to hear of the Crown Prince's death: "He served the Kingdom of Saudi Arabia for many years with great dignity and dedication.
"His contribution to the prosperity and development of the Kingdom will long be remembered.
"I would like to offer my sincere condolences to the Kingdom and its people at this sad time."
The Prince of Wales was said to have sent a personal letter of condolence to the King of Saudi Arabia.
A Clarence House spokesman said: "The Prince of Wales sent a personal letter of condolence to the King of Saudi Arabia expressing his deep sadness at the news."
AP reported the Crown Prince had had a string of health issues: he underwent surgery in New York in February 2009 for an undisclosed illness and spent nearly a year abroad recuperating in the United States and at a palace in Agadir, Morocco.
According to AP, the report did not say where outside the kingdom he died or elaborate on Sultan's illness.
