Pavosevic's lawyer, Davor Cahun, said that his client was accused of abuse of office and powers and of conspiracy to commit offences and that during the interrogation she had denied all the accusations.
Pavosevic, who was dismissed from the post of the head of the HDZ accounting after auditors detected irregularities in the party's book-keeping in 2008, is suspected of conspiring with former Prime Minister Ivo Sanader, former customs chief Mladen Barisic and several CEOs of public companies to siphon funds from state institutions and public companies through the privately owned marketing firm Fimi Media.
According to media speculations, Barisic handed over siphoned money to Pavisic who also reportedly managed the party's slush funds.
The investigating judge is expected on Friday to decide on keeping Pavisevic in investigative detention.
USKOK is likely to request a month-long detention for the suspect.
The latest arrest comes ahead of Sanader's extradition from Austria to Croatia, which is expected in the coming days. In the Fimi Media scandal, USKOK investigators suspect 16 people of being involved in siphoning funds from state budget.