LOS ANGELES (CBS) — A lawsuit by 75 former NFL football players claims the league tried to hide the effects of concussions for 90 years, according to published reports.

TMZ reports the lawsuit was filed Tuesday in Los Angeles County Superior Court, and claims as far back as the 1920s, the NFL knew of the dangerous effects of concussions on players’ brains, but concealed those facts until June 2010.

The lawsuit says the NFL commissioned a study on traumatic brain injury in 1994, and concluded in 2004, that there was “no evidence of worsening injury or chronic cumulative effects” as a result of multiple concussions, TMZ reported.

Helmet manufacturer Riddell is also a defendant, the Web site reported.

The reported lawsuit comes just weeks after Hall of Famer John Mackey died at the age of 69, after a long battle with dementia that is believed to have been caused by the contact associated with playing football.

But the concussion crisis in the NFL has been in the headlines for several months, particularly since the suicide of former Chicago Bear Dave Duerson in February.

Last month, the Center for the Study of Traumatic Encephalopathy at the Boston University School of Medicine confirmed that Duerson had suffered brain damage stemming from concussions.