Legislators fear for the independence of the police force following the arrest of Christina Chan Hau-man, who is accused of assaulting a police officer. Chan, 22, has been accused of assaulting a policewoman during the fracas outside the central government liaison office at the end of the New Year's Day democracy march. The circumstances of her arrest have raised questions. 'There certainly seems to be an element of wanting to send out a warning, not just on Chan, but on others as well,' said Democratic Party chairman Albert Ho Chun-yan, adding that he did not think this was an isolated case of police using tactics to send a political message. However, Ho said he would await further developments before considering any follow-up action. Chan was among activists who broke a police cordon at the New Year's Day march, and has been involved in protests over the removal of Tsoi Yuen Tsuen villagers to make way for the express rail. On Thursday, the day before the Finance Committee meeting at which funding for the express rail link was debated, police interviewed Chan's parents. She was arrested on Saturday, but has not been charged and has to report on police bail at the end of February. Her lawyer, Civic Party member Alan Wong Hok-ming, said he did not want to speculate as to the motives of the police, but the circumstances did raise questions. 'For example, why did they need to use officers from the Organised Crime and Triad Bureau? They have her phone number, they obviously know where she lives, so why could they not phone her to ask her to come into the police station for an interview,' he asked. 'Why did they have to wait until she came out of a public event before arresting her in public?' Wong added that since Chan was exercising her civil rights during the protest at which she was arrested, the police should present clear evidence that she had intended to assault an officer. However Democratic Party legislator James To Kun-sun said the Organised Crime and Triad Bureau often handled cases that might be politically sensitive.