PRAGUE (Reuters) - A Slovak journalist shot dead with his girlfriend was probably targeted for his investigative work, police said on Monday, a case that has shocked the small central European country and highlighted public concerns about corruption.

Jan Kuciak, 27, had reported for the news site Aktuality.sk on fraud cases, often involving businessmen with connections to Slovakia’s 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 the “cruel assassination” of its journalist while the international group Reporters Without Borders (RSF) said it was appalled.

Slovakia’s leaders promised to bring the perpetrators to justice, with the government offering a 1 million euro reward for information leading to an arrest.

“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 transactions by firms linked to businessman Marian Kocner and connected to a Bratislava luxury apartment complex that became the centre of a political scandal last year.

Kocner could not be reached for comment on Monday but told the Slovak public broadcaster he had no connection to the case.

A long-time Bratislava-based investigative journalist, Tom Nicholson, told the news sits Dennik N that he had spoken to Kuciak a week ago about a case they both were looking at involving suspected Italian mafia abuse of EU funds in Slovakia.

“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,” Prime Minister Robert Fico said.

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

PROTESTS OVER ALLEGED CRONYISM

The case connected to the apartment complex helped touch off 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 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,” publisher Ringier Axel Springer Slovakia said in a statement.

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

A group of 14 editors-in-chief of Slovak publications released a statement calling on the state to solve the case and help to safeguard journalists’ work.

Fico convened an emergency meeting with Kalinak, the attorney general, the national chief of police and the head of the state intelligence service.

Kuciak’s killing dismayed EU officials, coming a few months after Malta’s best-known investigative journalist, Daphne Caruana Galizia, was killed by a car bomb.

“Shocked by the murder of a journalist in the EU. No democracy can survive without the free press, which is why journalists deserve respect and protection,” deputy European Commission chief Frans Timmermans tweeted. “Justice must be served.”