Friday July 18 at 3 p.m., Huang Qi's mother again came to Chengdu's Public Security Bureau Wuhou branch office. The authorities presented her with a formal arrest warrant. The charge that the authorities have framed Huang with is possessing state secrets. This morning, Huang Qi's mother again asked the police: "He has already been held longer than the allotted time. Why don't you release him?" Their response, "The case is still being investigated, he will certainly not be released." In the afternoon she was given the arrest warrant. We urge concerned overseas people to follow this case closely.

Sichuan authorities did not arrest Huang within the legal time limit, yet refuse to release him.
According to the criminal procedure code, a suspect must be charged within 37 days, otherwise they should be released. But the Sichuan authorities did not arrest Huang and did not release him.
http://news.boxun.com/news/gb/china/2008/07/200807181948.shtml