A Slovak court on Thursday acquitted a well-connected businessman, Marian Kocner, of ordering the 2018 murder of an investigative journalist and his fiancee, in a case that has rocked the nation.

"The crime was committed but it has not been proved that Marian Kocner and Alena Zsuzsova ordered the murder," Judge Ruzena Sabova presiding over the case said in her ruling. 

"The court therefore acquits the defendants," the judge said, only sentencing Kocner to a 5,000 euro ($5,900) fine for illegal weapons possession as 60 bullets were found in his house.

The multi-millionaire and two suspected accomplices were accused of the February 2018 killings of investigative reporter Jan Kuciak and his fiancee Martina Kusnirova.

Both 27, they were gunned down at home after Kuciak wrote several stories on graft and the shady dealings of the high-powered entrepreneur with ties to senior government politicians.

According to the prosecution, Kocner ordered Kuciak's murder in revenge for the articles detailing his various property crimes.

Businessman Marian Kocner was found not guilty of ordering the murder. Photo: AFP

'I am not a murderer'

In his closing speech in July, Kocner denied murder.

"I am not a saint, but I am not a murderer either. I'm certainly not a fool who wouldn't realise what a journalist's murder would lead to," he told the jury.

In June, he had addressed Kuciak's father in court saying: "I'm sorry about what happened to your son, believe me, but I have nothing to do with it."

Of the five suspects charged in the case, two have confessed their guilt and have already been sentenced. 

Zoltan Andrusko, an intermediary in the murder plot, was sentenced to 15 years in jail in December 2019 after agreeing to a plea bargain. 

Ex-soldier and contract killer Miroslav Marcek for his part received a sentence of 23 years from the court in April for gunning down the couple.

'Killings have roused Slovakia'

Prosecutors argued that Andrusko served as a go-between in the murder, hiring gunmen Marcek and his cousin Szabo at the request of his friend Zsuzsova, who was in turn following Kocner's orders.

The double murder plunged the country of 5.4 million people into crisis and triggered the largest demonstrations seen since the fall of communism.

Then-premier Robert Fico was forced to resign in March 2018 and was replaced by his populist left Smer-SD party deputy Peter Pellegrini.

But the opposition won this year's general election, paving the way for a new centre-right government led by Igor Matovic from the ant-graft OLaNO party. 

"The deaths of Jan Kuciak and Martina Kusnirova have opened the eyes of the Slovak people," Matovic told AFP in February.

Former justice minister Daniel Lipsic, the murdered couple's legal representative in the trial, echoed that sentiment, saying Slovakia was "apathetic" before the double murder.

"The killings have roused Slovakia," Lipsic told AFP.