Astros general manager Jeff Luhnow vows that the organization will investigate the claims of sign stealing and is hopeful these allegations won't mar the team's success. (1:15)

The Houston Astros used a center-field camera to help steal signs during their 2017 championship season, a former pitcher for the team told The Athletic, a practice that would have run afoul of rules against using technology for an advantage and has prompted an investigation.

Mike Fiers, who now pitches for the Oakland Athletics, told the website that he warned teammates with the Detroit Tigers and A's that Astros hitters had used a video feed piped into a monitor near the dugout to decode signs and relay them to hitters during games.

"I just want the game to be cleaned up a little bit because there are guys who are losing their jobs because they're going in there not knowing," Fiers said in the story. "Young guys getting hit around in the first couple of innings starting a game, and then they get sent down. It's [B.S.] on that end. It's ruining jobs for younger guys. The guys who know are more prepared. But most people don't. That's why I told my team. We had a lot of young guys with Detroit [in 2018] trying to make a name and establish themselves. I wanted to help them out and say, 'Hey, this stuff really does go on. Just be prepared.'"

Later Tuesday, the Astros released a statement.

"Regarding the story posted by The Athletic earlier today, the Houston Astros organization has begun an investigation in cooperation with Major League Baseball," it said. "It would not be appropriate to comment further on this matter at this time."

At the winter meetings, Astros general manager Jeff Luhnow said the team wanted to gather facts before discussing the matter further.

"I have heard what you all have heard, which is allegations," he said. "This isn't the first one I heard and it's not the first one you all have heard. Like I said, I think the best course of action is not to speculate right now. We are going to look into it with cooperation of the MLB and we will find out what there is."

Allegations of cheating by the Astros have chased the organization for years, going back to its World Series victory in 2017 against the Los Angeles Dodgers. Opponents playing at Houston's Minute Maid Park are on constant lookout for signs of subterfuge, sources from multiple teams told ESPN. Before the World Series this year, members of the Washington Nationals organization received warnings from others around the game to beware of everything from flashing lights to whistling to a person relaying signs from the train that runs above left field, sources told ESPN.

The line between truth and fiction with the Astros has long been blurry, as the organization's reputation and success have made it a target for accusations of fanciful, complicated and unconfirmed methods of cheating. Fiers' joining three unnamed sources in alleging the use of the video feed is the strongest indication yet that Houston went beyond the accepted sign-stealing practice of not using technology to aid it.

"That's not playing the game the right way," Fiers said in the story. "They were advanced and willing to go above and beyond to win."

play 2:01 Wilbon: Astros stealing signs to me is not a big deal Michael Wilbon says that while allegations that the Astros stole signs with a camera is a big deal to some people, it's not in his opinion.

Fiers, a nine-year veteran, was non-tendered by the Astros after the 2017 season, when they won the World Series.

Fiers told The Athletic that he has a strained relationship with the Astros and that he informed his subsequent teams about Houston's sign-stealing practice.

MLB declined comment through a spokesman, referring to its statement given to The Athletic, which said the league issued a revised policy before the 2019 season that included new rules to preclude the use of video in stealing signs.

The league has looked into the Astros multiple times in recent years, with the first known incident in August 2018, when the A's alleged that Astros players were clapping in the dugout before pitches to relay stolen signs. During the playoffs that year, Kyle McLaughlin, whose current LinkedIn profile lists him as a member of the Astros' baseball operations staff, was removed by security during Houston's series against both the Cleveland Indians and the Boston Red Sox after pointing a phone toward the teams' dugouts from a nearby camera well. Luhnow later said the Astros were simply trying to ensure their opponents weren't using technology to steal signs.

After Game 1 of the American League Championship Series this season, the New York Yankees alleged that a whistling noise had emanated from the Astros' dugout, prompting fears Houston was stealing signs. It was similar to the allegations from multiple players in past years who told ESPN that players in the Astros' dugout would bang on a trash can with a bat to signal what type of pitch was coming to the plate, which The Athletic's story corroborated. The Astros denied the Yankees' accusations about whistling.

MLB has not publicly addressed any wrongdoing found in past investigations into the Astros.

The league currently is looking into the team after assistant general manager Brandon Taubman taunted female reporters in the aftermath of their victory against the Yankees. The team denied a Sports Illustrated report on Taubman's actions, issuing a statement accusing the publication of fabricating the story. The Astros later fired Taubman, retracted the statement and apologized to the reporter.

Luhnow was asked Tuesday whether he is concerned that the team's reputation has taken a hit.

"I hope it doesn't," the GM said. "We have a lot of great players, we have a really good manager and fan base and we have accomplished a lot. I think that stands for itself; I'm hopeful we will find out exactly what happened and we will address it if it needs to be addressed and we can move on. The reason we won the World Series in 2017 [was] Jose Altuve and Alex Bregman and Justin Verlander, and we have a lot of great players. They do things the right way, and we as an organization, that's what we aspire to do as well."