Minhai, a Swedish citizen originally from Hong Kong, disappeared on October 17, 2015 while on holiday in Pattaya in Thailand. The writer ran a publishing company known for publishing books critical of the Chinese government.
Minhai's condition and exact location was still unclear as of late Tuesday morning.
"There's no information really about where he is. In a way, the situation feels worse than before, because at least previously you had a clue about where he was, and now you don't," his daugther Angela Gui told Swedish Radio. "He has basically disappeared again."
#GuiMinhai has been disappeared again, likely by the Chinese government.— Angela Gui (@angelagui_) October 24, 2017
In January 2016, China's state-controlled CCTV channel broadcast an interview in which Minhai said that he had returned to China to face charges over a traffic accident.
At the same time, Chinese media reported that he had been detained.
His daughter has led a campaign for his release and said, in a press release on Tuesday, that saying her father was "freed" was premature.
"It is hence not clear how ”free” Gui Minhai is now, or when he will be allowed to return to Sweden and unite with his family," she wrote.