Saudi Arabia's attorney general says at least $100bn (£76bn) has been misused through systemic corruption and embezzlement in recent decades, reports BBC.
Sheikh Saud al-Mojeb said 199 people were being held for questioning as part of a sweeping anti-corruption drive that began on Saturday night.
He did not name any of them, but they reportedly include senior princes, ministers and influential businessmen.
"The evidence for this wrongdoing is very strong," Sheikh Mojeb said.
He also stressed that normal commercial activity in the kingdom had not been affected by the crackdown, and that only personal bank accounts had been frozen.
Sheikh Saud al-Mojeb said investigations by the supreme anti-corruption committee, which was formed by royal decree and is headed by 32-year-old Crown Prince Mohammed Bin Salman, were "progressing very quickly".
He announced that 208 individuals had been called in for questioning so far, and that seven of them had been released without charge.
"The potential scale of corrupt practices which have been uncovered is very large," the attorney general said.
"Based on our investigations over the past three years, we estimate that at least $100bn has been misused through systematic corruption and embezzlement over several decades."
Sheikh Mojeb said the committee had a clear legal mandate to move on to the next phase of its investigation and that it had suspended the bank accounts of "persons of interest" on Tuesday.
"There has been a great deal of speculation around the world regarding the identities of the individuals concerned and the details of the charges against them," he added.
"In order to ensure that the individuals continue to enjoy the full legal rights afforded to them under Saudi law, we will not be revealing any more personal details at this time. We ask that their privacy is respected while they continue to be subject to our judicial process."
Those detained reportedly include the billionaire investor Prince Alwaleed bin Talal and Prince Miteb bin Abdullah, who was also removed as National Guard chief.
Meanwhile, according to a report by www.dailymail.co.uk Saudi Arabia could seize $800 billion in assets from the kingdom's elite as part of its anti-corruption purge.
So far at least 11 princes and 38 former government ministers have been detained in the crackdown ordered by Crown Prince Mohammed bin Salman, though there are said to be more names on the hit list.
They have all had their bank accounts frozen and risk having their assets and properties seized by the government as it attempts to flush out fraud in Saudi Arabia.
Meanwhile, Saudi billionaires are racing to get their assets out of the kingdom before officials seize $800 billion of funds.
Some of Saudi Arabia's richest families are in talks with banks and asset management companies to shift their fortunes so that their money and properties are not captured by the anti-corruption sweep.
While some wealthy Saudis are selling investments in neighbouring countries to turn them into cash or liquid holding overseas, according to half a dozen sources close to the trade deals who talked to Bloomberg.
The uncertainty in the region has also had an impact on investors, who are selling off their stock pushing the indexes lower.
On Tuesday, Gulf investors sold $92.5 million worth of Dubai stocks, the most since February.
As the net is cast wider by government officials, the hierarchy are said to be eyeing up cash and assets worth around $800billion, according to Wall Street Journal who quoted sources close to the matter.
It is believed the number of those detained has now reached more than 60, but that the government is watching more notable figures.
