The government is swooping on members of the country’s elite as it looks to transform the conservative state into a modern country that is no longer dependent on oil.
Its latest purge has seen leading businessmen and over 60 princess, officials and high-profile Saudis arrested so far.
He said: “They reckon they could get around two to three trillion riyals from these people.
“That’s the number they are talking about.”
The kingdom’s central bank has already frozen a huge number of accounts as it bids to bring cases against some of those arrested.
Many of those frozen assets are said to be based abroad which will mean a long and complex process.
Saudi Arabia’s Crown Prince Mohammed bin Salman has ordered the a crackdown, the latest in a wave of frenetic changes in the kingdom over the past two years.
Dozens of royal family members, officials and business executives have already been held in a new purge announced on Saturday.
They face allegations of money laundering, bribery, extortion and exploiting public office for personal gain.
A number of other individuals suspected of wrongdoing were detained in an expansion of the crackdown, widely seen as an initiative of the powerful heir to the throne.