From the China Daily, via english.sina.com:
Accusations labeled by some overseas organizations and people that China has arrested “dissidents” to ensure the safety and security of the Olympic Games are “groundless”, a Beijing Olympic Games spokesman said Monday.
“To ensure a successful Games, and to ensure the safety of athletes and visitors, China has taken a series of necessary, legitimate and reasonable security steps. This falls in line with routines of previous Games and major international sports events,” Xinhua quoted the spokesman as saying.
The accusations (of arrest of “dissidents”) are “untrue and groundless”, he said.
China is committed to protecting human rights and some basic freedoms, including freedom of speech. The rights and freedom enjoyed by the Chinese people in accordance with the law are fully protected, and unbiased people recognize that fact, he said.