Cardiff City boss Neil Warnock made players pay to be selected for games, a committee of MPs has heard.
The claims were made by Jason Puncheon, who played under the experienced manager at Crystal Palace in 2014, in a series of now-deleted tweets.
Damian Collins MP, the chair of the parliamentary culture, media and sport committee, raised the issue during a hearing on football governance on Monday afternoon.
Collins used his parliamentary privileges to discuss the allegations, without fear of legal redress, which suggested that Warnock used his power for monetary gain.
Warnock has since denied the claims made by Puncheon, saying in a statement: "These allegations are completely and utterly false. The FA Commission considered all of the evidence in detail in 2014 and it found that the allegations which were published about me were unfounded.
"In fact, Mr Puncheon apologised to me and removed the allegations from his Twitter account. The FA fined him £15,000 and he was warned as to his future conduct. I am disappointed that these allegations have been repeated after Mr Puncheon's apology and after the FA investigated fully."
Warnock took charge of Cardiff earlier this month following the sacking of Paul Trollope, guiding the Bluebirds to a 2-1 win over rivals Bristol City in his first game at the helm.