Police in Slovakia have arrested an unknown number of suspects in the murder of investigative journalist Jan Kuciak and his fiancee Martina Kusnirova, a case that brought down the Slovak government.

Euronews reported that “at least one suspect” has been arrested as the Slovak police announced it had detained several people suspected of violent crime and was carrying out home searches. However, the police did not make any mention of the Kuciak case.

On Thursday, Prime Minister Peter Pellegrini said on Facebook that he was happy to receive news of the arrests while Daniel Lipsic, a lawyer representing the families of Jan Kuciak and Martina Kusnirova, said the suspects were arrested early on Thursday.

Last week, a delegation of MEPs from the European Parliament’s committee on civil liberties visited Slovakia and Malta to assess the rule of law and to look into the ongoing investigations into the murder of Kuciak and Maltese journalist Daphne Caruana Galizia.

Jan Kuciak and his girlfriend Martina Kusnirova were murdered at their home in February 2018

In a press conference, the MEPs said that the investigation into the murder of Kuciak and his fiancée “seems to be advancing”.

“Justice needs to be served, first for the families of the victims, but also to guarantee the safety of all journalists and for the sake of democracy,” the head of delegation Sophie in ‘t Veld said.

Kuciak and Kusnirova were assassinated in their home on 21 February and Slovak authorities said they believed it was a contract killing linked to Kuciak’s work investigating possible widespread government corruption and ties between politicians and Italian mobsters.

The killings triggered a political crisis that resulted in major protests, the dismissal of the national police chief and the collapse of the social democrat government led by Robert Fico.