Abrupt departures, unexplained empty broadcast chairs, unused microphones and abandoned Twitter accounts point to something very wrong at state-run China Central Television, Beijing’s broadcast monopoly.

In the past month and a half, colleagues count at least eight people who have stopped turning up for work following the arrest of the channel’s financial news director in early June, according to Zhan Jiang, a journalism professor at Beijing Foreign Studies University. Close observers suspect the rest have also been detained for investigation, amid a wide-ranging investigation into alleged corruption at the station.

These include Rui Chenggang, one of China’s most celebrated news anchormen. Six days after his last broadcast, there is still no official word on his fate. He vanished on Friday from the airwaves with no explanation, a day after tweeting “I’ll see you on the air in a bit” from his account on Weibo, China’s version of Twitter. His chair and microphone were left empty on set, as his co-host led the broadcast Economic News with no reference to her absent colleague. A day later, the People’s Daily, China’s communist party mouthpiece, announced he was in the custody of prosecutors on charges of corruption. Calls placed to CCTV went unanswered.