Helsinki police have launched a preliminary investigation into Yle's coverage of alleged bribery by executives of the defence contractor Patria.
Two of the company's former managers filed a complaint last May over Yle reports linking them to corruption. They were Heikki Hulkkonen, former Executive Vice President of Patria's Vehicles Business Unit and Reijo Niittynen, project manager for the company's operations in Slovenia.
Inspector Harri Saaristola, who is heading the probe, says it is being investigated as a case of aggravated libel. He declined to provide more details about the probe.
Prime minister sued Yle
Yle's investigative news show MOT broadcast programmes about bribery suspicions at Patria in 2008 and 2012, alleging that Patria bribed former Slovenian prime minister Janez Janša.
As a result, Janša sued Yle and its reporter Magnus Berglund for damages. A district court in Ljublana dismissed those charges in early 2014. A few months later Janša was sentenced to two years in prison on corruption charges.
The case dates back to 2006, when Slovenia decided to buy 135 armoured vehicles from the Finnish company for 278 million euros.
Last year a subsidiary of Patria and two of its former executives were convicted of corruption in a similar case involving materiel deliveries to Croatia. Other bribery cases have focused on Patria deals in Austria and Egypt.
Patria is majority-owned by the Finnish state.