The mystery surrounding the disappearance from Hong Kong of a publisher who sold books critical of China’s top leaders has taken another twist after his wife asked police to cancel her missing person’s report.

Hong Kong police said his wife, who reported Lee Bo missing last week, tried to rescind the report on Monday but they were still investigating the case “in a proactive manner”, in line with rules that only the missing person themselves can close such a case.

Meanwhile, Taiwan’s state news agency published a handwritten letter that it said had been faxed by Mr Lee to a colleague at their Causeway Bay Bookstore, in which the publisher said that he had gone to the mainland urgently and of his own volition to “co-operate with a relevant investigation”.