New England coach Bill Belichick — under fire for his team using underinflated footballs in the AFC Championship Game — said Saturday that the Patriots had studied and simulated the process of ball preparation and he believes they “absolutely followed every rule to the letter.”

The NFL is investigating the Patriots after 11 of 12 game balls they used in their 45-7 win over the Indianapolis Colts in the AFC title game were found to be underinflated.

“I believe now 100 percent that I personally and we as an organization have absolutely followed every rule to the letter,” Belichick said.

“I am embarrassed to talk about the amount of time that I’ve put into this relative to the other important challenge in front of us,” he said, referring to preparations to play the Seattle Seahawks in the Super Bowl on Sunday, Feb. 1.

“At no time was there any intent whatsoever to try to compromise the integrity of the game or gain an advantage. Quite the opposite. We feel like we follow the rules of the game to the letter in our preparations, in our procedures and the way that we handle every game we play as it relates to this matter.”

Belichick referenced his team’s previous punishment for taping opponents’ practices in the 2000s and said, “We try to do everything right. We try to err on the side of caution. It’s been that way now for many years. Anything that’s close we stay as far away from the line as we can. In this case, I can say, as far as I know, in everything that I can do, we did everything as right as we could do it.”

By rule, balls are supposed to be 12.5 to 13.5 pounds per square inch (PSI). Belichick said his team’s study found that typical preparation of the game balls — which involves rubbing them to get the preferred texture and feel for the quarterback — raises the pressure by one PSI in a controlled environment but that once the balls are in the elements for any amount of time they can lose up to 1.5 PSI.

Belichick denied any suggestion that the balls were prepared in a heated room.

“At no time were any of our footballs prepared anywhere other than in the locker room or in an area very close to that,” he said. “Never in a heated room or heated condition. That has absolutely never taken place to anyone’s knowledge or anyone’s recollection. That didn’t happen.”

Belichick said the footballs are delivered to the game officials, who are responsible for setting the pressure to the proper range, and the footballs are not touched again except for in the game.

At halftime of the AFC title game, the 11 footballs were found to be two pounds below the required pressure. The NFL was alerted and began an investigation after the game.

“We welcome the league’s investigation into this matter,” Belichick said. “I think there are a number of things that need to be looked into on a number of levels. But that’s not for this conversation. I am sure it will be taken up at another time.

“This is the end of this subject for me for a long time. We have a huge game, a huge challenge for our football team, and that’s where that focus is going to go. I’ve spent more than enough time on this.”