Updated

Beijing is warning outside groups against seeking to intervene in the case of a Taiwanese pro-democracy activist detained in China, saying that would complicate matters and harm relations between the sides.

Taiwan Affairs Office spokesman An Fengshan said Lee Ming-che, who was taken into custody on March 19, was under investigation for endangering China's national security. An told reporters at a biweekly news conference Wednesday that Lee's legal rights were being protected, but said he had no other information about his case.

Lee's wife was prevented on Monday from flying to Beijing to seek a meeting with her husband after China canceled her travel permit.

China, which claims Taiwan as its own territory, cut off its already limited contacts with the island's government in June.