The Boston Red Sox have sacked manager Alex Cora as a result of his role in the "sign-stealing" scandal during his time as Houston Astros bench coach.
Cora, 44, managed the Red Sox to a World Series victory in 2018.
But a Major League Baseball (MLB) investigation into the Astros found he played a key role in the use of a camera to steal signs being given by catchers to pitchers in 2017.
A separate MLB investigation into the Red Sox is yet to conclude.
"This is a sad day for us," the Red Sox said in a statement. "Given the findings and the commissioner's ruling, we collectively decided that it would not be possible for Alex to effectively lead the club going forward and we mutually agreed to part ways."
MLB suspended Astros general manager Jeff Luhnow and manager AJ Hinch for a year without pay for their role in the scandal, and the pair were subsequently fired by team owner Jim Crane.
The Astros were also fined $5m (£3.8m), and made to surrender draft picks.
While Cora was mentioned 11 times in the nine-page report, MLB commissioner Rob Manfred said he would defer any disciplinary action on the Boston manager until the ongoing investigation into the Red Sox - over the alleged use of their video replay room to steal signs during their 2018 title-winning season - was completed.
Cora, whose playing career included four seasons with the Red Sox, had been Hinch's number two during 2017, when the Astros won the World Series - before returning to Fenway as manager, where he won baseball's biggest prize again a year later.
He said: "I do not want to be a distraction to the Red Sox as they move forward.
"My two years as manager were the best years of my life. It was an honour to manage these teams and help bring a World Series championship back to Boston. This is a special place. There is nothing like it in all of baseball, and I will miss it dearly."
What is 'sign stealing'?
It happens when teams monitor what finger signs a catcher is using to request specific deliveries - such as a fastball, curveball or slider - from his pitcher.
MLB rules prohibit the use of electronic equipment to steal signs but otherwise the practice, while frowned upon, is not against the rules.
A report in The Athletic claimed the Astros would monitor catchers' signals via a camera in the outfield, before banging on a rubbish bin inside the clubhouse to signal to the batter that an off-speed pitch was expected.
A subsequent story, also in The Athletic, alleged that Boston players had visited their video replay room, before relaying information to team-mates on the field.
Back in September 2017, the Red Sox were fined by MLB for using an Apple Watch to steal signs from the New York Yankees.
After that incident, MLB issued a specific warning to all 30 teams over technology.