Major League Baseball officials investigating whether the Houston Astros cheated over the past three seasons by electronically stealing signs have asked players associated with the organization what they know about a range of alleged sign-stealing techniques, sources familiar with the conversations told ESPN on Friday.

Players have been asked about "buzzing," via the use of Band-Aid-like wearable stickers; furtive earpieces; pitch-picking algorithms; and other potential methods of sign-stealing, the sources said. Accusations about the extent of the alleged wrongdoing have streamed into commissioner Rob Manfred's office from officials of other teams, the sources said. MLB officials are endeavoring to separate fact from fiction, the sources told ESPN, and the league has not concluded whether any such methods actually have been used.

Players who might have violated league rules have been told by MLB officials they can expect leniency in exchange for answering questions truthfully. But members of the Astros' front office and coaching staff could face significant punishment upon the investigation's conclusion if they're found to have cheated, the sources said. The league has requested to search the phones of certain members of the Astros' front office, the sources said.

Major League Baseball's biggest scandal in years began this month when former Astros pitcher Mike Fiers told The Athletic that the 2017 World Series-winning team he was a member of used video from a live camera feed to steal a catcher's signs, and that someone in the dugout would hit a trash can to communicate the pitch type to batters in real time.

Stealing signs through electronic means is against MLB rules, and the story prompted an MLB investigation that Manfred said this week will be "as thorough as humanly possible" and also will encompass the 2018 and 2019 teams. The inquiry, the sources told ESPN, includes examining a wide swath of sign-stealing theories.

Skepticism about the Astros' motivations and tactics dates back years and has contributed to the accusations against the Astros -- most of which have been delivered without supporting evidence. Players nevertheless have been asked if they know about the Astros relaying signs through earpieces, decoding signs with an algorithm or even using wearable technology embedded in Band-Aid-like items or worn in shoes that could signal pitches electronically.

The league is hoping to determine both the depth of the Astros' alleged transgressions as well as how high knowledge of them went in the organization, the sources told ESPN. Kevin Goldstein, a special assistant to Astros general manager Jeff Luhnow, sent an email to scouts in 2017 inquiring about them spying on opposing dugouts using video cameras.

MLB declined comment through a spokesman.

Investigators' conversations with players have followed those with Astros front-office employees as well as on-field staff, including current Astros manager AJ Hinch, former bench coach and current Boston Red Sox manager Alex Cora and former designated hitter and current New York Mets manager Carlos Beltran, the sources told ESPN. A number of current Astros players have not spoken with investigators yet but are expected to talk in the near future, the sources said. Multiple players no longer in baseball have refused to cooperate with the investigation, according to sources familiar with their decision.

Sign-stealing, long considered an art in baseball, has entered a far more complicated moral and ethical space with the alleged use of technology. The illegality, Manfred said this week, is clear: After the Red Sox were disciplined for using an Apple Watch to relay signs in September 2017, MLB threatened significant penalty for teams that parlayed technology into an advantage. He reinforced that notion following the 2018 postseason, during which an Astros baseball-operations employee was removed from the camera well in two playoff series for pointing a cellphone camera toward opponents' dugouts. MLB instituted new rules that included an audit on in-stadium cameras, an eight-second delay on in-house video feeds and other restrictions meant to preclude cheating.

The outrage among opposing teams, simmering for years, boiled upon Fiers' statements, the sources said. At this week's owners meetings in Arlington, Texas, multiple team owners and presidents told ESPN they hoped Manfred would levy heavy sanctions on the Astros if they're found to have cheated -- which could include individual suspensions for executives, losses of draft picks and international bonus slots, and a fine in excess of the maximum $2 million the league has applied for past infractions -- to deter others who might see the value in cheating.

The wariness toward the Astros has manifested across the game in unique ways. One American League starter, according to sources familiar with his routine, asked if he could pitch a game with his catcher not giving standard, between-the-legs signs. The pitcher instead wanted to communicate what he intended to throw with a series of jersey pulls, hat tugs, head shakes and glove placements. During this year's World Series, in which Washington defeated Houston in seven games, the Nationals came armed with five unique sign sequences for pitchers, ready to change them at any time, because they feared the Astros had a new method to steal them, sources said.