A Taiwan resident has been detained on suspicion of harming national security, Ma Xiaoguang, spokesman for the State Council Taiwan Affairs Office, said at a news conference on Wednesday.
Lee Ming-che, who Ma described as "being in good health", was reported missing on March 19 while in Macao.
According to previous media reports, he had planned to attend a meeting later that day in Zhuhai, Guandong province, but failed to show up.
The authority has been notified of the request by Lee's family to send him money and other goods, said Ma, adding that judicial procedures were underway.
