RIYADH The United States voiced doubts over the health of Saudi Arabia's elderly Crown Prince Sultan in a diplomatic cable in May 2009, writing that he was "incapacitated", according to website WikiLeaks.
Top oil exporter Saudi Arabia has sought to quash speculation on the health of Sultan, who is thought to be in his mid-eighties and was treated for an unspecified sickness for much of the past two years.
Sultan, who officially stands in line to inherit the throne, rushed home last month from a three-month break in Morocco after King Abdullah, who is around 87, sought medical treatment in New York.
"Crown Prince Sultan has been incapacitated by illness for at least (the) past year," the U.S. embassy in Riyadh wrote in a cable in May 2009. At the time Sultan was in Morocco for rest after medical treatment in the United States.
Abdullah, who underwent surgery in New York last week after a blood clot complicated a slipped spinal disk, has asked Sultan to run the kingdom, a staunch U.S. ally, during his absence.
Saudi officials say Sultan is working normally. State media this week showed pictures of him chairing a cabinet meeting and receiving Saudi officials.
But diplomats in Riyadh say Sultan has been treated for cancer and seem to have unofficially delegated duties to other princes since his return in December following an absence abroad for almost a year.
With both Abdullah and Sultan in their 80s, the next in line would be conservative Interior Minister Prince Nayef, at a relatively youthful 76. Nayef would still need the approval of Saudi Arabia's "Allegiance Council" to become king.
Abdullah appointed his half-brother Nayef second deputy prime minister in 2009 in a move that analysts say will secure the leadership in the event of serious health problems afflicting the king and crown prince and improve Nayef's chances of one day being king.
(Reporting by Ulf Laessing; Editing by Ron Askew)