The PM said he expected the assets of eight suspects from the Croatian Privatisation Fund (HFP) to be frozen if they were proven guilty, and all unlawfully acquired property to be returned to the state.
Sanader said that the operation, dubbed "Maestro", had dealt a powerful blow to a centre and possibly the heart of corruption, bribery and organised crime in Croatia.
The government created legal conditions and secured funds to carry out the operation, the PM added.
Asked if he trusted Deputy PM Damir Polancec who has dismissed claims by Ivan Gotovac, a HFP vice-president who was arrested, that Polancec had known about murky dealings in the HFP, Sanader said he trusted the State Prosecutor's Office and services that had monitored HFP officials for more than a year.
Sanader said that he had known about the operation, but he would not say since when. He added that he had proposed that the government adopt a decision to set aside 800,000 euros for operations to counter corruption and organised crime.
President Stjepan Mesic knew about the operation as well, and already last year the state leadership was determined to put an end to corruption, Sanader said.
The operation continues and four institutions - the State Auditor's Office, the Tax Administration, the Office for the Prevention of Money Laundering and the Croatian Financial Services Supervisory Agency - have just become involved in the investigation, Sanader said, adding that there would be more information soon.