【明報專訊】AI WEIWEI was taken away at Beijing's airport on April 3. The mainland's public security authorities are required by the criminal prosecution law to inform the family or work unit of a detainee within twenty-four hours of his detention. The authorities erred when they broke this rule. In the small hours of April 7, Xinhua, a government-controlled news agency, released a story that quoted the police as saying Ai was suspected of economic offences and was under investigation according to law. The story, in which "suspected" is used, counted as an official confirmation of what had become of him. At that stage, though the authorities had committed procedural improprieties, the Ai case was on the whole handled in a normal way.