A black sedan with dark windows follows Xu Jiehua when she rides her motorcycle through her village on the shores of Tai lake, China’s third-largest. A policeman sits outside her back door all day; another waits by the front gate.

It has been this way since her husband, Wu Lihong, one of China’s best-known environmental activists, was arrested in April. He is held at a nearby police station but his family – who deny the charges – are not allowed to see him and his lawyer claims he has been tortured.