UPDATE SUNDAY: Since I posted the story yesterday, several people working on the show have come forward to confirm Chase’s version of the events. One noted that the show indeed was “suffering through a ‘non-script day'” when Chase walked off. Another claimed that most of the cast and crew members who attended the wrap party disapproved of Harmon’s behavior at the bash.

PREVIOUS: Things are looking up for NBC’s perennial bubble series Community, which has been solid since returning from a long hiatus earlier this month, establishing itself as NBC’s second highest-rated comedy behind The Office. But behind the scenes, a rift between co-star Chevy Chase and creator/executive producer/showrunner Dan Harmon has escalated into an ugly war of words.

Accounts of the feud have leaked online, including on social news website Reddit. The chronology of the events, corroborated to me by multiple sources, involves Chase walking off the set of the show on the last day of shooting last month without filming one of his scenes, which reportedly was to close out the season finale. Then at the wrap party, Harmon got up and gave a “Fuck you, Chevy” speech in front of Chase and his wife and daughter, and encouraged the crew to join him in saying “fuck you” to the actor. Chase left immediately and later left Harmon a profane-laden voice message, a portion of which found its way to the Web after Harmon played it in front of other people. Click here for audio. (Warning: foul language!) In the voice message, Chase addresses both his storming off the set, which he attributes to not getting the script beforehand, (some say it’s because he didn’t find the scene funny) and the wrap party incident.

People close to the matter told me they weren’t surprised by the feud, noting that Chase already had a reputation of being difficult before signing on for Community. (I hear it was NBC’s former boss Ben Silverman who championed Chase for the project and was instrumental in bringing him on board.) Word is Chase has stormed off the set of the NBC show in the middle of a scene a number of times and has also gotten into arguments with Community executive producers-directors Anthony and Joe Russo. There had been tension between Chase and Harmon, and with both of them described as “passionate” or “volatile,” depending who you talk to, a blowup was “inevitable,” one person said. Ironically, a recorded Chevy Chase phone call played a major role in another feud involving the Saturday Night Live alum, that with shock jock Howard Stern.

It is unclear at the moment what impact the falling-out between Harmon and Chase would have on Community and whether Chase would continue on the show. The producers’ attention right now is focused on securing a fourth-season renewal for the offbeat comedy, which appears more and more likely. The pickup is key to the syndication prospects of the series, which has an off-network deal with Comedy Central as well as a non-exclusive pact with Hulu. While he was the biggest name when Community launched, the series has made stars out of several of its little known supporting players, with Joel McHale firmly established as the show’s leading man. Still, Community has benefited Chase, boosting his sagging career with a role on a hip show.