Saudi Crown Prince Naif bin Abdul Aziz has died at an overseas hospital, the royal court announced on Saturday. He was 78, dpa reported.
A special funeral prayer is to be held for him on Sunday in the holy city of Mecca, the court added in a statement. It did not specify the cause of his death.
He died in a hospital in Switzerland, the Dubai-based broadcaster Al Arabiya reported without giving further details.
Naif was appointed the oil-rich country's heir apparent in October after the death of his brother, Sultan.
Earlier this year, he went to the United States to undergo what the royal court called "scheduled medical tests."
He had served as interior minister since 1975 and became a second deputy prime minister in 2009.
His appointment as heir to the throne raised concerns, with some pro-reform analysts saying he could halt reforms introduced by King Abdullah bin Abdul Aziz.
