A watchdog investigating complaints against the Hong Kong police said on Thursday the force turned down some of its requests for information related to recent anti-government protests.The force said some of the photographs and video clips sought by the Independent Police Complaints Council (IPCC) were needed for prosecution purposes.Tony Tse Wai-chuen, vice-chairman of the IPCC, said a special task force set up to look into police use of force in recent protests had received more than 23,000…