"We will decide the fate of this confiscated money when we find out what it is... [Until then, it will] lie quietly here," Orban said at a campaign event in Debrecen.
The prime minister told the rally that a pro-Ukrainian party had been created in Hungary from scratch in the run-up to April's parliamentary elections. He suggested that the effort required a significant amount of funding.
"We do not know whether this money was being taken out or brought in here. The truth is, we just want to know what the Ukrainians were doing with this huge sum of money in Hungary. We really want to know. What is happening seems suspicious to me," Orban said.