A key ally of the Slovakian prime minister, Robert Fico, has been forced to resign as interior minister after the murder of a journalist who had been investigating links between the government and the Italian mafia.



Robert Kaliňák, who also quit his post as deputy prime minister, said the country’s need for stability required him to leave the administration.

The Slovakian government has been in crisis since the discovery of the bodies of the investigative reporter Ján Kuciak, 27, and his fiancee, Martina Kušnírová, in their home last month. The couple were due to marry in May.

Kuciak had specialised in investigating corruption and fraud. His stories had included individuals with whom Kaliňák had a business relationship.

Fico’s partners in the coalition government, the Most–Híd party, had accused Kaliňák of having a conflict of interest in his role as head of the department to which the criminal investigators would ultimately answer. Kaliňák had been given until Monday to leave or face the fall of the administration.

“I think to fulfil my mandate I have to do everything to preserve stability in Slovakia,” he said. “For this reason I have decided to resign as deputy prime minister and interior minister.”

The murders of Kuciak and Kušnírová prompted tens of thousands of people to protest on the streets of Bratislava over the weekend, calling for the fall of Fico’s government.

Police have said Kuciak’s death was “most likely” related to an unfinished investigation into the ties between senior Slovakian politicians and Italy’s ‘Ndrangheta organised crime group.

Kaliňák is the second minister from the Smer party to resign over the murders. Marek Maďarič resigned as culture minister, saying he could not accept that a journalist had been shot dead during his tenure. An international team of journalists has been formed to complete Kuciak’s story.

An estimated 40,000 people gathered in Bratislava to protest on Friday against Fico’s government. It was Slovakia’s biggest demonstration since the 1989 Velvet revolution that toppled communism in former Czechoslovakia.

Protesters holds placards during a rally to pay tribute to the murdered Slovakn journalist Ján Kuciak. Photograph: Joe Klamar/AFP/Getty Images

Thousands of others rallied in other cities across Slovakia, with parallel demonstrations also taking place in Prague and Berlin.

Kaliňák said he would stay on to complete unspecified tasks before formally stepping down, without giving a date.

Earlier this month, Slovakian police detained seven Italians named by Kuciak in his story, only for them to be released 48 hours later.

The Most–Híd party is expected to meet later on Monday to decide whether Kaliňák’s resignation is enough to keep it in the coalition that also includes the rightwing Slovak National party (SNS).

Fico’s alleged link to the mafia was his close aide Mária Trošková, a former model and Miss Universe contestant who was also close to the businessman Antonino Vadala, one of the detained Italians. Trošková and another Fico aide have both stepped down for the duration of the investigation.

The Slovakian president, Andrej Kiska, has called for sweeping government changes or even snap elections after the Kuciak murder, and is in talks with all the coalition parties over the next steps.

Fico initially criticised the president’s call as “an attempt to totally destabilise our country”, only to later accept the seriousness of his position.

“We will offer solutions that will enable Most–Híd to continue in the government. I perceive the reality and I am ready for talks,” he said last week.

AFP contributed to this report