If only Tom Brady had been a bit more accurate…

The investigation of illegally under-inflated footballs possibly being used by the Patriots in their AFC Championship Game triumph Sunday began following a second-quarter interception of Brady by Colts linebacker D’Qwell Jackson, a source told Newsday.

Jackson, picking off a pass intended for tight end Rob Gronkowski near the goal line with the Patriots ahead 14-0, returned to the Colts sideline and gave the ball to a member of the team’s equipment staff. That person reportedly noticed the ball seemed under-inflated and notified coach Chuck Pagano, who passed the information up the food chain to general manager Ryan Grigson, who contacted NFL director of football operations Mike Kensil.

After Kensil told the game referees at halftime, additional Patriots footballs may have been removed from circulation. New England also scored 21 points in a dominant third quarter, with the refs now on alert, to take a 38-7 lead.

The league’s Deflategate probe is expected to take several days to resolve. And to think it all started because of a rare Brady miscue.