The Houston Astros won the World Series in 2017 after scoring the most runs in baseball in the regular season. They also had the most total bases and the highest team batting average.

And according to a report by The Athletic today, they often knew what pitches were coming because of a scheme using a camera and a trash can.

The report said the Astros, in violation of major league rules, had used a camera in center field to capture signs from opposing catchers to the pitchers at Minute Maid Park in Houston, transmitted images to a monitor near the dugout and then relayed information to the batter by banging on a trash can.

Mike Fiers, a former Astros pitcher who is now with the Oakland Athletics, joined some anonymous sources in confirming the caper, and the Astros said Major League Baseball was looking into the matter.

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

Players and coaches may use their eyes to steal signs, but the use of electronics is forbidden. MLB confirmed that it was investigating the information in the report.

Fiers, who pitched for Houston from 2015 to 2017, told The Athletic that when he left the Astros to pitch for the Detroit Tigers and the Athletics, he warned his new teammates to beware at Minute Maid Park.

“I had to let my team know, so that we were prepared when we went to go play them at Minute Maid,” he said.

Andrew Friedman, the president of the Los Angeles Dodgers, who lost the 2017 World Series to Houston, said today that the team heard concerns about the Astros that year.

“I know during the playoffs, our advance team that was on Houston talked about it,” he said. “There was just a lot of speculation at the time about it.”

But Friedman added: “From our standpoint, being that we were one of the teams involved, it sounds like sour grapes for us to comment too much on this.”

Though the article focused on the 2017 season, there is also evidence that the Tampa Bay Rays were suspicious of the Astros during Game 5 of their American League Division Series last month. In that game, the Rays used three sets of signs even when there were no runners on base, a clear indication that they were concerned the Astros were using illicit means to steal signs.

After that game, Rays catcher Travis d’Arnaud detailed how his team had used the extra signs as a precaution. Rays left fielder Austin Meadows was also asked about it, and he referred to the fact that the Astros had scored four runs in the first inning of that game.

“I really have no comment on that,” he said. “I don’t know if there’s cameras or not, but obviously they did a good job putting four on the board early in the game, and that kind of shifted momentum to their side.”

Before the New York Yankees played the Astros in this year’s AL Championship Series, Houston manager A.J. Hinch was asked about the Rays’ suspicions.

“Everybody is worried about pitch-tipping, and everybody’s worried about stealing signs across the league,” Hinch said. “Everybody’s doing it, not just to us, but to everybody. I’ve watched so many games this year where everybody is paranoid that they’re giving something away. We were running through multiple signs with nobody on base because that’s the era that we’re playing in. You’ve got to guard against every advantage that you think somebody can get.”