Earlier reports had suggested that he was preparing to cough up a cash settlement in return for his freedom, although the reported breakdown of those talks led to suggestions that he may he put on trial.
In an interview with Reuters on Saturday (Sunday NZ time), shortly before his release, Alwaleed said he did not face any formal charges.
"Settlements don't happen unless the accused acknowledges violations and documents that in writing and pledges that he won't repeat them", the official said.
"The attorney general this morning approved the settlement with Prince Al-Waleed bin Talal", a government source told AFP.
The government has released other high-profile detainees in recent weeks such as former National Guard chief Prince Miteb bin Abdullah following his "settlement" with authorities reportedly exceeding $1 billion.
He was initially thought to have been killed in a firefight while resisting arrest, but Saudi Arabia's Information Ministry later confirmed he was "alive and well".
His web of hospitality and real estate investments includes the George V hotel in Paris, New York's Plaza hotel and the Savoy hotel in London.
Mr Waleed al-Ibrahim, head of the Dubai-based Middle East Broadcasting Centre, and Mr Fawaz Al Hokair, the billionaire founder of one of the country's largest retailers, were among those sent home, a government official said on condition of anonymity.
Earlier reports indicated that MbS was asking Alwaleed had been refusing MbS demand of giving -up ownership of the entire Kingdom Holding Company.
Prince Alwaleed said his own case was taking longer to conclude because he was determined to clear his name completely, but he believed the case was now 95 percent complete. With the suspects' names and evidence against them never officially announced, the detentions had raised concerns about transparency among foreign investors - vital to Crown Prince Mohammed bin Salman's plan to diversify the economy away from oil.
While declaring his innocence in the Reuters interview, the prince appeared greyer and thinner than in his last public appearance, a television interview in October, and had grown a beard while in detention. "I'm so comfortable, I'm like at home, frankly speaking". I shave here, like at home.
His suite at the Ritz-Carlton included a private office, dining room and kitchen.
His refrigerator was stocked with vegetarian meals as requested, and he had tennis shoes for exercise, Reuters reported. Although few people doubt Saudi Arabia would benefit from less corruption, the scale and ferocity of the crackdown alarmed businessmen inside and outside the kingdom.