A report has accused New England Patriots quarterback Tom Brady of being aware that balls were under-inflated during the AFC championship game last season.
The Patriots beat the Indianapolis Colts 45-7 in torrential rain to book their place in the Super Bowl, but claims were immediately made that they had deliberately deflated balls to give Brady an advantage.
An investigation was launched and it has concluded that the Patriots are 'probably' guilty of the offence.
The report, by NFL vice-president Jeff Pash and attorney Ted Wells, says: "It is more probable than not that New England Patriots personnel participated in violations of the Playing Rules and were involved in a deliberate effort to circumvent the rules.
"Based on the evidence, it also is our view that it is more probable than not that Tom Brady was at least generally aware of the inappropriate activities."
The Patriots went on to win the Super Bowl by beating the Seattle Seahawks.