Two princes, sons of the late King Abdullah, were released two months after they were detained in an anti-corruption crackdown, a source close to the government said.
"They have been released," AFP quoted the source as saying a day after a family member posted photos of Prince Faisal bin Abdullah, a former head of the Saudi Red Crescent, and Prince Mashal bin Abdullah, a previous governor of Mecca, on Twitter.
The source said that Prince Turki bin Abdullah was the only brother left in detention. Another brother, Prince Miteb bin Abdullah, former National Guard chief, was released in November after three weeks in detention following a settlement with authorities reportedly exceeding $1 billion (Dh3.67bn).
The four brothers were among more than 200 royals, officials and businessmen detained on charges of corruption in a crackdown led by Crown Prince Mohammed bin Salman.
Most of those detained have struck monetary settlements in exchange for their freedom, the attorney general said this month. Meanwhile, those who continue to deny charges against them will soon face trial.
Last week, major Saudi newspaper Okaz reported that 23 people were released after reaching settlements with the authorities.
Other high-profile targets of the crackdown include billionaire Prince Al Waleed bin Talal, dubbed the Warren Buffett of Saudi Arabia.
The detainees have been held at Riyadh's Ritz Carlton hotel and other five-star hotels in the capital.
Saudi authorities said the purge was meant solely to target endemic corruption as the kingdom seeks to diversify its oil-dependent economy.
The attorney general has previously said he estimates at least $100 billion has been lost in embezzlement or corruption over several decades.