In the complaint, which is to be dealt with by a Supreme Court judge, Gredelj argues that the building housing the party headquarters was acquired lawfully before 2003, and that "it could not have been financed with money from slush funds even theoretically."

In a statement for the public, Gredelj says the court ruling he was challenging did not contain any grounds for suspicion that any of the money from alleged slush funds could have ended up in the HDZ's property after 2003 either, and that those funds could have possibly ended up as part of the property of persons who received payments from the alleged slush funds, which he said was yet to be established by the investigation.

"Since there is no doubt that before 2003 the HDZ acquired its property lawfully (from budgetary funds, membership fees, donations etc.), and it is unclear which of the HDZ's property acquired after 2003 could have been acquired unlawfully, we believe that the temporary ban is unfounded," Gredelj said in the statement for the media.

He said the complaint had been submitted for the sake of transparency of the party's operations, which he said was part of a new strategy of leading the party, with Jadranka Kosor at the HDZ's helm.

Gredelj added that another reason for the complaint was the fact that the party was aware of the public's waning trust in the HDZ and therefore wanted citizens to decide for themselves if the complaint was founded or not.

Zagreb County Court spokesman Kresimir Devcic said investigating judge Erna Drazancic would forward the complaint and the case file to the Supreme Court. A Supreme Court judge will decide on the complaint, and Devcic said that there was no defined time frame within which the complaint had to be dealt with.

Gredelj believes that the ruling will be made soon due to the importance of the case and the great interest of the public.

He would not talk about steps to be taken next by the HDZ, saying only that he would address the public again once he studied the case file.

In late October, acting at the request of the anti-corruption investigating agency USKOK, the Zagreb County Court banned the HDZ from freely disposing of the building housing its offices. The temporary ban was imposed with the aim of securing compensation for the state in case the suspected irregularities are proven in court. The ban forbids the HDZ to sell the property or to mortgage it.

USKOK has been investigating the HDZ for a year and a half in a corruption scandal named after the Fimi Media marketing agency which is believed to have been used by the party to syphon money from state-owned companies, agencies and government ministries. Since it suspects that some of the syphoned money ended up in the party's slush fund and was used, among other things, to finance the party's election campaigns, USKOK has expanded the investigation to the HDZ as a legal entity.

The USKOK investigation in the Fimi Media case now covers 19 suspects and the HDZ as a legal entity.