4. What are the consequences if I refuse to cooperate with the police when they are exercising their powers to stop, question or search me?
It first depends on whether or not the police have proper legal basis to do the act concerned (see the earlier Q&As as to the circumstances when the police can lawfully stop, question or search a person). If not, then the police officers concerned are not acting in due execution of their duties, and one may refuse to cooperate. If yes, then one must in general cooperate with the police, as it is an offence for a person to assault, resist or deliberately obstruct the police in the execution of their lawful duties (see for example, section 63 of the Police Force Ordinance and section 36 of the Offences Against The Person Ordinance). The maximum penalty for such an offence is imprisonment of two years.
Moreover, any Hong Kong resident aged 15 or above who without reasonable excuse fails to produce proof of identity (showing his ID card or passport) for inspection by the police upon demand commits an offence and is liable to a fine of $5,000 ( section 17C of the Immigration Ordinance).
However, even if the police can lawfully ask you questions, you have a right to silence and so may refuse to answer any questions posed by the police (except that you may need to provide your name and address to the police).