He was speaking at an HDZ Main Committee session held on the occasion of the party's 18th anniversary.
Sanader said that the Maestro operation, in which six Croatian Privatisation Fund (HFP) officials were arrested yesterday, was evidently not over and did not only refer to the HFP.
He said the HDZ wanted all rule of law institutions to do everything to suppress organised crime and corruption to the lowest possible level.
Commenting on some opposition party leaders' demands that the government be held politically accountable in the wake of Maestro, Sanader said such reactions were "absolutely inappropriate" since no one knew what the outcome would be when the operation was launched.
He added that numerous citizens had congratulated the government in the last 24 hours supporting the operation and more similar ones in the future.
The HDZ is asked to be the first in the fight against every form of radicalism or extremism, which the party has shown by condemning both the Ustasha ideology and communism, but not antifascism, said Sanader.
He mentioned that the HDZ had passed a constitutional law on cooperation with the Hague war crimes tribunal and that it viewed minorities not as a threat but as a chance for Croatia's society.
That is why we shall not stop here and if it is established that the arrested HFP officials committed crimes in privatisation, the HDZ will ask that the unlawfully acquired property be returned to the Republic of Croatia, said Sanader.
In his message to the opposition leaders, he said the HDZ would again win elections later this year and that their attacks on the party were "just another shot in the dark".
The Main Committee adopted a conclusion supporting all state bodies and the government in the fight against corruption and demanding that corruption be eradicated.
Justice Minister Ana Lovrin presented figures indicating the efficiency of the judicial reform, saying that pending cases had been cut by 30 per cent.