Janša is one of the three persons indicted along with two former directors of companies that took part in multiple transactions, Branko Kastelic and Klemen Gantar, according to the newspaper.
The case revolves around a plot of land in the Trenta Valley in the Alps that Janša bought in 1992 and sold in 2005, at the time when he was prime minister the first time, for roughly EUR 131,000, nearly nine times the price he paid.
The buyer, the property developer Eurogradnje, then sold the plot, land along a river accessible only via a footbridge, for EUR 146,000 in 2005 to another company, Imos. The same year, Imos sold Janša a three-room apartment in the centre of Ljubljana for EUR 236,100.
The prosecution claims Eurogradnje paid EUR 100,000 more for the land than it was worth, which was then factored into the price of the apartment.
When Imos went bankrupt, the value of the plot was officially appraised at EUR 17,655, but then the plot was sold for EUR 127,500 at an auction won by Damjan Podjed, raising accusations about the price being artificially inflated to help Janša.
However, in August 2018 Podjed sold the plot to another person for EUR 140,000. Neither Podjed nor the final buyer appear among the suspects for now.
Janša has vehemently denied all allegations of wrongdoing since they first surfaced in the media in 2011. He has stressed that he has made enough money in his career with salaries and multiple bestselling books and has cast the allegations as part of a plot by people behind the scenes to remove him from politics.
The Trenta transaction was one of the allegations against him in a 2011 report by the Commission for the Prevention of Corruption.
The alleged criminal offence carries an eight-year prison sentence and is subject to a 20-year statute of limitations.