Campaigner Dawn Astle has accused football's authorities of shoving a study into head injuries "in a drawer".
The death of Astle's father Jeff in 2002 was determined by a coroner to be the result of a neurodegenerative condition caused by repeated heading of a ball during his professional football career.
Astle told MPs on the Digital, Culture, Media and Sport (DCMS) committee that she wrongly assumed that finding would be the catalyst for research.
"A coroner said there was trauma all the way through the brain, every slice of my dad's brain had trauma in it," she said.
"We assumed incorrectly that the inquest ruling would be a defining moment and the sport would react with vigour to protect future generations and to help football's past heroes."
She said research started in 2001, funded by the Football Association and the Professional Footballers' Association, had been mothballed until it was challenged to produce it.
"It wasn't published; nobody had the courtesy to tell me or my family. But more importantly, this was 12 years after my dad died and we were no further forward.
"This study was only published when we challenged the PFA and the FA as to where it was, and I believe that study was shoved in a drawer.
"That drawer was locked, and it only came out because we challenged where it was, and that's not good enough."
Former footballer Chris Sutton, whose father Mike died with dementia last December, said: "This meeting we are having today should have happened 20 years ago.
"The fact of the matter is the authorities haven't done anywhere near enough, they have ignored, they have shunned, they have turned their back on what has been a massive issue.
"Hundreds of players have died – my father included. This is something we need to deal with, and deal with fast.
"Even if you don't agree with any of the research that's out there, there are simple preventative measures that can be put in place now which can help generations to come."
Sutton said the permanent concussion substitute protocols which had been approved by the game's lawmaking body last year "don't have the players' welfare and health at heart".
He also called for clubs to limit heading in training to a maximum of 20 per session and allow a minimum of 48 hours between those sessions.
"We don't need to keep having meetings about meetings about this, this needs to happen immediately," he said. "Hundreds if not thousands of players have died from dementia and if we don't get on top of this now, hundreds or thousands more will die.
"It's really important the Government take ownership of this, because the FA and the PFA haven't done anywhere near enough."
