The NFL found the New England Patriots used deflated footballs during the AFC Championship, according to a report from Chris Mortensen of ESPN. According to the report, the league sources say the NFL determined 11 of the 12 footballs used by the Patriots were under-inflated by two pounds per square inch each. Per NFL rules, footballs are required to be inflated between 12.5 and 13.5 PSI and weigh between 14 and 15 ounces.

While Mortenson cites league sources, the NFL is yet to comment on the investigation. The Patriots maintain they will cooperate with the NFL. Reports about under-inflated footballs used by the Patriots surfaced only a few hours after the AFC Championship ended. The NFL and the Patriots responded the following day, with the league saying it would look into the matter and expected to resolve the investigation quickly.

The inflation of the footballs may not have come into question had Tom Brady not thrown an interception. According to reports, D'Qwell Jackson handed the ball he intercepted to a member of the equipment staff. That person then told Colts head coach Chuck Pagano of the issue with the ball. Word was eventually passed on to Indianapolis general manager Ryan Grigson and Mike Kensil, NFL director of football operations.

SB Nation presents: What every Pats fan is thinking about DeflateGate

According to Ben Volin of the Boston Globe, game officials discovered the issue at halftime. According to NFL rules, if footballs do not meet required specifications, the referee is to use a conforming football from the visitor side. If there are no conforming footballs, the closest to proper specifications should be used. The issue must also be reported to the league office.

NFL teams prepare their own 12 game balls, which are checked by officials prior to kickoff. After being checked, balls are given to an attendant who works with officials to rotate footballs in play. There is a separate set of kicking balls, used only for special teams.

With the investigation still ongoing, any potential punishment remains unknown. According to initial reports, the Patriots could be fined and even docked draft picks if the league determines the balls were intentionally deflated.