Though the latest allegations are big news in Poland, they are unlikely to change many Poles' minds about Lech Walesa.
The claim that he collaborated with the communist secret police in the first half of the 1970s goes back about a quarter of a century.
The controversy re-emerged in 2008 with the publication of a biography, The Security Services and Lech Walesa, by two historians from the Institute of National Remembrance, Slawomir Cenckiewicz and Piotr Gontarczyk.
The book alleged that Mr Walesa was registered as an informant, code-named "Bolek", by the communist secret police in 1970, and that he passed on information in return for money until 1976.
"Walesa was the agent Bolek… he betrayed friends and colleagues," Mr Cenckiewicz said on Thursday.
For those who dislike Mr Walesa, and there are many in the Law and Justice party that governs Poland today, his youthful actions were those of a traitor.
But others took a more nuanced view of the allegations, especially if they had lived through the communist period and knew that applying for a passport in those days meant an interview with the secret police,
In 2008, people who were prepared to believe that Mr Walesa had been an informant as a young man told me that it mattered little because of his crucial role in helping to restore democracy and freedom to Poland in 1989.
The now 72-year-old former president was the man who led the Solidarity trade union from its creation in Gdansk's Lenin shipyard in 1980, to a mass movement with 10 million members that was driven underground until it re-emerged to defeat the Communist Party in the Soviet bloc's first partially free elections in 1989.
For that, he is still a living legend in the minds of many Poles.
I interviewed Walesa myself at the time of the 2008 book's publication and while he said he had had meetings with the secret police, he insisted he did not sign any documents agreeing to collaborate.
He said the communist authorities faked documents about him to try to ruin his reputation after he became Solidarity's leader, adding that a court cleared him of the allegation when he ran unsuccessfully for a second term as president in 2000.
According to Donald Tusk, a former Polish prime minister who now heads the European Council, what is at stake here is not just Mr Walesa's reputation, but also the story of the rebirth of a free Poland in 1989.
Speaking on Thursday, Mr Tusk called the latest allegations, "unfortunate from the point of view of Poland's image, this great tradition and legend of Solidarity and Lech Walesa".
He added that he was surprised by the emotions the affair has raised again because "really Lech Walesa has never hidden that he had some contacts and problems [with the secret police] in the 70s".