Dubai: Senior Saudi Prince Miteb bin Abdullah, once seen as a leading contender to the throne, was freed after reaching an "acceptable settlement agreement" with authorities paying more than $US1 billion ($1.3 billion), a Saudi official said on Wednesday.

The son of the late King Abdullah was head of the elite National Guard, and was among dozens of royal family members, ministers and current and former senior officials who were rounded up in a corruption inquiry at least partly aimed at strengthening the power of Crown Prince Mohammed bin Salman.

The official, who is involved in the anti-corruption campaign, said Miteb was released on Tuesday after reaching "an acceptable settlement agreement".

"The amount of the settlement was not disclosed but it is believed to be more than one billion US dollar equivalent," the official said.