Poland's special prosecutors say they are investigating whether former president and democracy icon Lech Walesa made false statements during sworn testimony.

Critics of the investigation say it's a new step taken by Poland's ruling party trying to belittle Walesa's role as leader and icon of the country's victorious pro-democracy struggles of the 1980s.

The investigation is linked to recently found communist-era documents that prosecutors say include Walesa's handwritten reports for secret security agents in the 1970s. During questioning by prosecutors of the National Remembrance Institute, Walesa denied he ever wrote or signed them, and said they had been fabricated.

A top prosecutor, Andrzej Pozorski, said Tuesday an investigation into the veracity of Walesa's statements was opened in June.

It wasn't clear when conclusions could be expected.