This time it’s Sheraton hotel workers claiming retribution, including by being asked to show their immigration-related papers.

It’s happening again. The NBCUniversal campus, already a flashpoint for Hollywood’s ongoing labor unrest, as the writers and actors guilds have alleged picket-busting, is now the site of a new strike controversy. This time, Unite Here Local 11, the Southern California hospitality union that’s also currently staging walkouts, is claiming that the Sheraton Universal is retaliating against its workers for protesting.

According to an unfair labor practices charge filed Aug. 18 with the National Labor Relations Board, the organization contends that the hotel has issued disciplinary notices against 16 employees, including multiple suspensions, in retribution for picketing outside of the property, which is a short stroll past the primary NBCUniversal gate, where Writers Guild and SAG-AFTRA members have themselves been massing and marching.

Unite Here says that Sheraton Universal management has unlawfully conducted surveillance on employees, has made threats against them to dissuade them from participating in the protests and has also demanded “immigration-related documents from worker leaders in retaliation for workers’ protected concerted activities.”

Sheraton Universal declined to comment. It’s owned by Shenzhen New World Group. The firm and its billionaire real estate developer owner, Wei Huang, were sentenced earlier this year by a federal judge in a public corruption case involving the bribing of the former Los Angeles City Councilman José Huizar. The company was sentenced to five years of probation for fraud and bribery. Huang, who’s yet to make a court appearance and is believed to be in China, is a fugitive from justice.

Unite Here, which backed the Hollywood unions early on in the strike by announcing that it would help enforce the production shutdown, began its historic work stoppage in early July. About 15,000 members — including housekeepers, dishwashers and bellmen — are pushing for higher wages as well as more affordable health insurance, a ban on discrimination based on immigration status and other considerations.

The WGA and SAG-AFTRA filed their own NLRB complaints against NBCUniversal in July over their belief that the studio had infringed on their members’ right to picket as well as their safety by obstructing the public sidewalk in front of the lot. A city agency also cited the company for illegal sidewalk tree pruning, which the guilds believed was suspiciously timed to eliminate shade amid a summer heat wave. NBCUniversal has any denied foul play and has since partially restored the footpaths.

The WGA and SAG-AFTRA didn’t return requests for comment about the Sheraton Universal situation. Members of both unions attended a solidarity rally Aug. 17 for Unite Here workers who are employed as commissary workers at NBCUniversal.