A SLOVAK journalist and his girlfriend were shot dead in their home in an attack likely linked to his work on exposing tax evasion, Slovakia’s top police officer said.

The bodies of 27-year-old Jan Kuciak and his partner were found on Sunday evening in their house in the town of Velka Maca, east of the capital Bratislava, police president Tibor Gaspar said.

Officers had gone to the house at the request of a worried family member.

Gaspar said the killings probably have something to do with Kuciak’s “investigative activities”.

Prime minister Robert Fico said if that was the case, it would be “an unprecedented attack on freedom of the press and democracy in Slovakia”.

Fico announced his government was offering ¤1 million (£880,000) to anyone who helps authorities find those behind the killings.

President Andrej Kiska called for a swift investigation of the crime. He said: “We have to find those who did it as soon as possible and ensure the safety of all journalists.”

Gaspar said the reporter was shot in the chest, while the woman was shot in the head. They were estimated to have been killed between Thursday and Sunday.

He added that Slovakia “has never faced such an unprecedented attack on a journalist”.

Kuciak was working for the Aktuality.sk news website. He focused mainly on tax evasion.

In his latest story, Kuciak reported on a businessman suspected of selling flats in an apartment complex to his own companies. The reporter questioned the business reasons for doing that, and speculated that it could be a method of avoiding tax.

Kuciak said last year he filed a complaint with police after the businessman, Marian Kocner, threatened him following another story. Kuciak then complained that police had failed to act.