Saudi Arabia has announced the end of a high-profile anti-corruption probe ordered by Crown Prince Mohammed bin Salman that boosted the state coffers by more than $100 billion and left dozens detained.

The crackdown on corruption launched in 2017 saw hundreds of elite princes, ministers and businessmen held at the luxury Ritz-Carlton hotel in the Saudi capital. Many were detained for weeks in the upmarket hotel, but most were released after agreeing significant financial settlements.

According to a statement released by the official Saudi Press Agency (SPA), the corruption investigation concluded on Wednesday with the approval of King Salman bin Abdulaziz.

A royal court statement said the government had summoned 381 people, some as witnesses, under the campaign launched in November 2017. It said 87 people confessed to charges against them and reached secret settlements that included the forfeiture of real estate, companies, cash and other assets, according to SPA.

The public prosecutor refused to settle the cases of 56 individuals due to already existing criminal charges against them, the statement added.

The cases of eight people were referred to the public prosecutor after they refused to reach settlements.

During the probe, over 400 billion Saudi riyal ($107 billion) were recovered by the state "in the form of real estate, companies, cash and other assets".

The figure matched that announced a year ago by the Attorney General, who at the time said 56 suspects remained in custody.

Saudi's anti-graft sweep led by the Crown Prince was labelled by some critics as a shakedown and power grab, but authorities insisted the purge targeted endemic corruption.