PRAGUE: A Slovak journalist shot dead with his girlfriend was probably killed because of his investigative work, police said on Monday, in a case that has shocked the small central European country and highlighted public concerns over graft.

Jan Kuciak, 27, had reported for news server Aktuality.sk on fraud cases, often involving businessmen with connections to the ruling party and other politicians. He and his girlfriend were found dead on Sunday at his home in Velka Maca, 65 km (40 miles) east of the capital Bratislava.

Aktuality’s publisher Axel Springer condemned what it called the “cruel assassination” of its journalist, and Slovakia’s leaders promised to bring those responsible for the killings to justice.

“From the information available it seems that the most likely version is a motive connected to the investigative work of the journalist,” Slovak police chief Tibor Gaspar told a televised news conference.

Kuciak’s last story for Aktuality, on Feb. 9, looked at new suspect transactions by firms linked to businessman Marian Kocner and connected to a Bratislava luxury apartment complex that became the center of a political scandal last year.

Kocner could not immediately be reached for comment on Monday.

PROTESTS

The case connected to the apartment complex prompted protests in 2017 seeking the resignation of Interior Minister Robert Kalinak over business dealings with property developer Ladislav Basternak, who has been investigated over possible tax fraud. Both have denied any wrongdoing in their dealings.

“We are shocked and stunned about the news that Jan Kuciak and his companion obviously have been the victims of a cruel assassination,” Ringier Axel Springer Slovakia said in a statement.

It said there were “justified suspicions” that the murder was connected to Kuciak’s “current research”. It declined to say what that research involved due to the pending criminal investigation.

Slovakia’s leaders condemned the killings.

“We have to find those who did this as soon as possible and secure the safety of all journalists, using all the means we have,” President Andrej Kiska said in a statement.

Prime Minister Robert Fico convened an emergency meeting over the killings with Interior Minister Kalinak, the state general attorney, the national chief of police and the head of the state intelligence service.

“If it is proven that the death of the investigative reporter was connected with his journalistic work it would be an unprecedented attack on freedom of speech and democracy in Slovakia,” Fico said in a statement.

Slovakia’s economy has boomed and living standards have risen sharply since it joined the EU in 2004, but many Slovaks say their country still fails to defend the rule of law, especially in punishing graft.