General manager Jeff Luhnow and manager AJ Hinch have been fired by the Houston Astros after they were suspended without pay for a year by Major League Baseball for their role in sign stealing during their 2017 World Series success.
MLB had been investigating claims the team illegally used a camera to steal signs from catchers to pitchers during the season.
Former Astros pitcher Mike Fiers and three anonymous sources told The Athletic in November that the Astros used a camera in the outfield during home games.
The Astros have been fined $5m (£3.8m), the highest amount permitted, and they forfeit their first- and second-round draft picks for 2020 and 2021.
According to the ruling, the investigation revealed "absolutely no evidence" that Astros owner Jim Crane was aware of any of the team's conduct.
Boston Red Sox manager Alex Cora, who was a Houston coach in 2017, is also named in the report and could face a ban.
In addition, MLB is investigating claims that the Red Sox used video replays to steal signs from catchers to pitchers during their 2018 World Series-winning season, following a second report by The Athletic.
Catchers flash signs to pitchers using their fingers to call for a specific delivery - such as a fastball, curveball or slider - and knowing what pitch is likely to be coming is an advantage to the batter.
MLB prohibits the use of electronic equipment to steal signs but otherwise the practice, while frowned upon, is not against the rules.
The first Athletic report claims that during the 2017 season, Astros players and staff would monitor opposing catchers' signals as recorded by a camera at Minute Maid Park.
After working out which sign corresponded to which pitch, they would tell the batter what was coming, allegedly banging on a rubbish bin inside the clubhouse to signal an off-speed pitch.
The Astros won their only world title in 2017, beating the Los Angeles Dodgers in game seven of a thrilling series.
They were beaten 4-3 by the Washington Nationals in last year's World Series.
Fiers, 34, was not offered a new contract in Houston after the end of the 2017 season, having been left off their roster for the post-season. He moved to the Detroit Tigers for 2018, and is currently with the Oakland Athletics.
"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.
The suspensions of Luhnow, Hinch and Brandon Taubman are to begin immediately, the bans to end on the day following the completion of the 2020 World Series.
Former assistant general manager Taubman, who was dismissed by Houston in October, is also banned for a year without pay.
'Significant harm to the game'
"I find that the conduct of the Astros, and its senior baseball operations executives, merits significant discipline," commissioner Rob Manfred said as part of the nine-page ruling.
"The conduct described herein has caused fans, players, executives at other MLB clubs, and members of the media to raise questions about the integrity of games in which the Astros participated. And while it is impossible to determine whether the conduct actually impacted the results on the field, the perception of some that it did causes significant harm to the game."
Should either Luhnow or Hinch be found to engage in "any future material violations" of MLB rules in the future, they will receive a lifetime ban.
The report says former bench coach Cora, who is now the manager of the Red Sox, was involved in setting up the illegal recordings.
Cora was not disciplined as part of this investigation, but the report states that he could face penalties at the conclusion of the ongoing investigation into allegations of illegal sign-stealing by the Red Sox during the 2018 season.
MLB opened a new investigation last week after The Athletic reported that the Red Sox had used their video/replay room during the 2018 season to learn opponents' sign sequences.