Jan Kuciak, 27, and his girlfriend, Martina Kusnirova, were found shot dead Sunday in their home in Velka Maca, east of the capital, Bratislava. According to police, about 10 people will be subject to investigation.
“Physical evidence and individuals are being detained,” Gaspar said.
In his unfinished investigative report, Kuciak described the activities of an organized crime ring active in an impoverished region of eastern Slovakia near the border with Ukraine. The report alleged connections between Slovak businessmen of Italian origin who embezzled European Union funds in coordination with 'Ndrangheta, a Calabrian mafia syndicate.
Gaspar said the detained men were “persons mentioned” by Kuciak in connection to the “Italian track.”
Kuciak detailed ties between Antonino Vadala, a member of the group who had moved from Italy to Slovakia, and officials in the government of Slovak Prime Minister Robert Fico. According to Slovak media, Vadala was among the three detained Thursday.
Several officials have already stepped down. Two of those mentioned by Kuciak resigned Tuesday, and they denied any connection to organized crime or the killings.
In a joint statement, Maria Troskova, a personal aide to Fico, and Viliam Jasan, chairman of Slovakia's national security council, denounced what they said was an attempt “by some politicians and the media to link our names to these repellent crimes.”
Jasan was a longtime business associate of Vadala's, and Troskova, a former topless model and beauty contestant with no previous experience in politics, was hired by Fico at Jasan's request.
Despite a public demand for answers, Fico has refused to acknowledge the possibility that top aides in his administration may have been involved in the alleged corruption or the killings.
“Do not link innocent people without any evidence to a double homicide,” he said in a news conference on Tuesday.
Kuciak is the first journalist to have been killed in Slovakia, and his death is being seen as an assault on the press in a country where it has generally been tolerated.
The European Center for Press and Media Freedom, a Germany-based nonprofit, dispatched legal adviser Flutura Kusari to Bratislava to monitor the investigation. According to her, the process is already being questioned.
“We are worried that an independent investigation will not be possible because most of the journalists we have been talking to believe that the police and prosecution are influenced by politicians,” Kusari said in an email.
Kusari said that Slovakia now joins Hungary, Poland, Malta, Bulgaria as E.U. member states “where press freedom is no longer guaranteed and being a journalist is becoming very dangerous.”
Police said they planned to release more details about the case later Thursday.