A faxed message from missing Hong Kong publisher Lee Bo to a colleague has surfaced stating that he is in China “cooperating with the authorities with an investigation,” The Washington Post reported, citing a report from Taiwan’s Central News Agency. The missive comes days after the Wednesday disappearance of Lee, whose company specializes in books critical of the party leadership, in what experts have said looks increasingly like an illegal abduction by Chinese police. Hong Kong police have claimed they have no record of Lee passing through immigration; he is also the fifth member of the publishing house Mighty Current to vanish.