Slovak Deputy Prime Minister and Interior Minister Robert Kalinak. Photo: File

Slovak Deputy Prime Minister and Interior Minister Robert Kalinak announced his resignation Monday following tensions sparked by the murder of an investigative journalist probing links between the government and the mafia.

"I think to fulfil my mandate I have to do everything to preserve stability in Slovakia," Kalinak told reporters. "For this reason I have decided to resign as deputy prime minister and interior minister."

Last month´s murder of Jan Kuciak and his fiancee prompted huge protests against the government of Prime Minister Robert Fico, with tens of thousands of Slovaks turning out for rallies in Bratislava on Friday.

Following the protests, Fico´s Smer-SD party, to which Kalinak also belongs, came under fire from small coalition partner Most-Hid, which threatened to quit if the minister stayed.

The bodies of Kuciak and his fiancee Martina Kusnirova, both 27, were found on February 25 at their home near Bratislava. The couple, who were to have married in May, had both been shot dead.

Police have said Kuciak´s death was "most likely" related to his investigation resulting in an article on ties between Slovakia´s top politicians and Italy´s notorious ´Ndrangheta mafia, which his employer posthumously published.

The murder and the article sparked a wave of anti-government sentiment in the EU and NATO member of 5.4 million people.

On Friday, some 40,000 people gathered in Bratislava to protest against Fico and his government, making it Slovakia´s biggest protest since the 1989 Velvet Revolution that toppled Communism in former Czechoslovakia.

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