CHICAGO (CBS) — The father of late Blackhawks player Steve Montador has filed a federal lawsuit against the National Hockey League, claiming the league failed to warn players about the potential long-term effects of repeated head trauma.

The complaint filed in Chicago alleges the NHL “utterly failed to provide (Montador) with crucial medical information on the permanent ramifications of brain trauma.”

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Montador, who retired in 2013, died in February at his home in Ontario. According to the lawsuit, an autopsy revealed he had chronic traumatic encephalopathy (CTE), a degenerative brain disease caused by repeated head trauma.

The Montador family’s lawsuit claims he was in 69 fights during his NHL career and “sustained thousands of sub-concussive brain traumas and multiple concussions, many of which were undiagnosed and/or undocumented.”

The lawsuit states Montador also suffered multiple documented concussions — including at least three in six months in 2003 while playing for the Calgary Flames, four more in nine months in 2010 while playing for the Buffalo Sabres and four within three months in 2012 while with the Blackhawks.

As a result of that repeated head trauma, Montador suffered “significant memory issues, sleep disturbances, chronic pain, a substance abuse problem, photosensitivity, mood and behavioral changes, decreased appetite, anxiety, and depression both during, and after, his NHL career,” the lawsuit stated.

The lawsuit alleges the NHL has long known players were vulnerable to developing CTA and other brain diseases, “as a result of the fist-fighting it allowed and promoted, the hard hits it encouraged and marketed, and/or the blows to the head that it steadfastly refused to eliminate from its game.”

In 1997, the NHL launched a program to study the effects of repeated head trauma, but Montador’s lawsuit alleges the league misled players and “simply sat on the data it collected” until 2011 and even then “found only ‘potential adverse effects’ from ‘continuing to play while symptomatic, failing to report symptoms to medical staff and failure to recognize or evaluate any suspected concussion.'”

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“All the report concluded, essentially, was that more education was needed about potential adverse effects,” the lawsuit alleges.

Montador’s attorneys also claimed the NHL failed to warn retired players of the dangers of repeated concussions they might have suffered while playing.

“As a result of its repeated decisions to bury its collective head in the sand, the NHL never conducted any proposed study on its retirees, apparently not wanting to confirm what it already suspected — that repetitive head trauma sustained in contact sports can, and does, lead to permanent brain damage,” the lawsuit states.

According to the Chicago Tribune, NHL deputy commissioner Bill Daly said the league stands by previous comments on the issue.

In June, NHL commissioner Gary Bettman said there has been no link established between CTE and playing in the NHL.

“From a medical science standpoint, there is no evidence yet that one necessarily leads to the other,” Bettman said. “I know there are a lot of theories, but if you ask people who study it, they tell you there is no statistical correlation that can definitively make that conclusion.”

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Montador’s lawsuit seeks unspecified damages from the league.