News report from BBC Sport
At a parliamentary hearing, Damian Collins mentioned a claim Warnock made players pay to be selected for games.
The claim was made by Jason Puncheon - who played under Warnock for two clubs - though he later withdrew it, accepted it was "unfounded" and apologised.
Puncheon was fined £15,000 by the Football Association in March 2014.
"These allegations are completely and utterly false," said Warnock in a statement.
"The FA commission considered all of the evidence in detail in 2014 and it found the allegations which were published about me were unfounded."
Warnock added: "I am disappointed that these allegations have been repeated after Mr Puncheon's apology and after the FA investigated fully."
Conservative MP Collins, the chair of the parliamentary culture, media and sport committee, was questioning Football Association chairman Greg Clarke and director of strategy Robert Sullivan at Monday's hearing on football governance.
He was speaking using parliamentary privilege, which allows politicians to raise allegations without fear of legal redress.
Collins said: "In January 2014 it was reported that Jason Puncheon, the Crystal Palace player, made allegations on Twitter regarding Neil Warnock - his former manager.
"The tweets have been deleted but they are available online and I'll read out the relevant bit.
"He said, 'What I won't accept is an opinion from a man who's crooked and ruining the game. The man who signs players, gives them extra wages and appearance bonuses to make sure they pay him to get into the team or on the bench. The fact that he can even talk about training is shocking. He was never there'."
Clarke was asked why the FA had not contacted Puncheon - who played for Warnock at QPR and Palace - to ask him why he made the comments, rather than fining him.
Clarke, who succeeded Greg Dyke in August, said he had not been in his job at the time, and was unaware of what had happened.
Sullivan, who was also giving evidence, said no action had been taken against Warnock because there has been no "hard evidence".
Warnock, 67, has managed 17 different clubs at Premier League and Football League level during a 36-year career in management.
He was appointed manager of Championship side Cardiff on 5 October and has been in charge for just one game - Friday's 2-1 win over Bristol City.