Dozens more people have been taken into custody by Saudi authorities, the kingdom said, bringing the number of detained princes and businessmen to 201 in a sweep investigators say has uncovered at least $100 billion in corruption.

Key points: Attorney-General says $100 billion has been misused through corruption, embezzlement

Attorney-General says $100 billion has been misused through corruption, embezzlement Detainees held in five-star hotels, about 1,700 bank accounts have been frozen

Detainees held in five-star hotels, about 1,700 bank accounts have been frozen Critics say the purge is Crown Prince Salman sidelining potential rivals to the throne

Saudi critics and experts have called the unprecedented purge of top princes and businessmen a bold and risky move by Crown Prince Mohammed bin Salman, aimed at consolidating power as he casts his eye toward the throne, sidelining potential rivals and dismantling alliances built with other branches of the royal family.

The sweep comes at a time of increased tensions between Saudi Arabia and its main regional rival Iran over the ongoing conflict and suffering in Yemen and a newly erupting political crisis in Lebanon.

Saudi Attorney-General Saud al-Mojeb said 208 people had been called in for questioning, and that seven were released without charge, leaving 201 in custody.

The figure is the first reported by the Government and far larger than what was previously known, reflecting a continuing series of arrests throughout the week.

The purge began overnight Saturday, initially catching 11 princes and 38 officials, military officers and business leaders. They are being held at five-star hotels, including the Ritz-Carlton in Riyadh.

The 32-year-old Crown Prince, who is the son of King Salman and is popularly known by his initials MBS, is leading the investigation as head of a newly formed anti-corruption committee.

Among those detained are billionaire Prince Alwaleed bin Talal and two sons of the late King Abdullah, including Prince Miteb, who until Saturday had headed the powerful National Guard.

Several years ago, he was considered a contender for the throne and was recently believed to be opposed to MBS becoming Crown Prince.

The Government declined to identify the individuals being questioned, saying it is respecting their privacy during this phase of the investigation.

An estimated 1,700 individual bank accounts have been frozen.

"The potential scale of corrupt practices which have been uncovered is very large," Mr al-Mojeb said, adding that based on investigations in the past three years, at least $100 billion has been misused through corruption and embezzlement.

Mr al-Mojeb confirmed that action was taken to suspend personal bank accounts, but he did not disclose any figures.

The Government stressed that only personal accounts have been frozen, leaving businesses untouched.

Saudis have complained for years of rampant corruption and misuse of public funds by top officials in a system where nepotism is also widespread.

In recent years, Saudi families have also had to contend with austerity measures that have driven up costs while simultaneously being told they can no longer count on cushy government jobs.

Saudi billionaire Prince Alwaleed bin Talal was believed to be opposed to MBS becoming crown prince. ( Reuters: Fahad Shadeed )

Purge part of plan to wean Saudi Arabia from oil dependence

Meanwhile, members of the sprawling royal family and their business associates had long been seen as operating above the law.

Members of the royal family receive undisclosed monthly stipends from state coffers built up over years of high oil prices.

After oil prices fell three years ago without fully recovering, Saudi Arabia introduced new taxes and lifted some subsidies in order to boost revenue and cut government spending.

Supporters of MBS say fighting corruption is part of the Crown Prince's Vision 2030 plan, a blueprint for how to restructure the country and wean it from its dependence on oil revenue.

Faisal Abbas, the Saudi editor-in-chief of the daily Arab News, wrote in a widely-shared column this week that the kingdom is "damned if it acts against corruption, damned if it doesn't".

"Anyone who understands who is who in Riyadh knows only too well that none of those arrested — whether royals or non-royals — has or would have had any political sway in the current climate whatsoever," he wrote.

"More importantly, it is just mind-boggling that very few are noticing the obvious; which is that all of those being detained are incredibly wealthy," Abbas added.

Still, independent Saudi observers say the anti-corruption probe targets only select members of the royal family, government and business community.

Additionally, several of those arrested were ministers under King Salman working on the Crown Prince's economic reforms, raising questions about where responsibility begins and ends.

World leaders refrain from comment on purge, Lebanon boycott

Saad Hariri announced his resignation as Prime Minister on the weekend. ( AP: Hassan Ammar, file photo )

French President Emmanuel Macron told journalists in the United Arab Emirates that he was not making any judgements.

"This is not the role of a president, and similarly I would not expect a leader of a foreign country to come and infringe on domestic matters," he said.

Mr Macron is expected to visit Saudi Arabia and meet with the Crown Prince on the crisis in Lebanon sparked by the sudden and mysterious resignation of Prime Minister Saad Hariri.

He announced his resignation in a pre-recorded message from Saudi Arabia earlier this week.

Hassan Nasrallah, the leader of Hezbollah and one of Lebanon's most powerful figures, has openly speculated that Saudi Arabia played a role in Mr Hariri's resignation and might have been held against his will in the kingdom.

Saudi Arabia ordered all of its citizens to "immediately" depart Lebanon amid heightened tensions with Hezbollah and the militant group's patron, Iran.

A brief statement carried by the state-run Saudi Press Agency also warned Saudis against travel to the country.

Kuwait, Bahrain and the United Arab Emirates have similarly warned their citizens against travel to Lebanon.

AP