Major League Baseball said it is looking into an incident during Houston's 7-2 win in Game 1 of the American League Championship Series in which an Astros employee appeared to be seen shooting video from the photographer's pit adjacent to the Red Sox's dugout.
MLB told Boston Metro, which was first to report on the incident, that the matter was being handled internally.
The Astros, major league sources tell ESPN's Buster Olney, had deployed the employee to monitor whether the Red Sox were doing anything outside the rules on their side of the field.
The incident -- which led to the employee being removed by security -- is expected to lead to nothing more than a fine for the Astros, according to sources. But it is also expected to be a topic of a wider discussion at next month's general managers meetings on the use of electronic devices during games.
Boston is managed by Alex Cora, who is in his first year on the job after serving as bench coach last season for the world champion Astros.
"I'm aware of something going on, but I haven't been briefed," Astros manager A.J. Hinch said after Tuesday's Game 3. "I'm worried about the game."
Cora said the situation is something for Major League Baseball to handle.
"Somebody mentioned [it] to me right now. That's an MLB issue," Cora said. "They'll do what they have to do. But I just heard today."
When pressed on whether he had any concerns about signs being stolen, Cora added: "I'm always concerned about that throughout the season. So I mean, we do a good job changing sequences and paying attention to details. And we don't get caught up in the whole paranoia thing of the signs. We try to slow it down. If we feel there's something going on, we switch the signs."
Dave Dombrowski, Boston's president of baseball operations, said MLB dealt with the issue early in the game.
"That didn't have anything to do with the game. Really, all I can say is it's in Major League Baseball's hands," Dombrowski said. "It was done early in the game, caught early in the game. There are things they were dealing with. It's in Major League Baseball's hands. But it did not cost us anything."
Cleveland.com reported Tuesday night that the Cleveland Indians filed a complaint with MLB about the Astros trying to film their dugout during Game 3 of the American League Division Series. Houston won that game to complete a three-game sweep.
Yahoo Sports reported Tuesday that Oakland Athletics players in August believed members of the Astros were relaying stolen signs during games and the team called to have the incident investigated. Yahoo couldn't ascertain whether the matter was resolved, or if the investigation remains ongoing.