Police say riot officers have been equipped with high resolution cameras since October, in part to protect them against “malicious and false allegations”.
At a meeting with the police watchdog on Tuesday, the force said the cameras can help make law enforcement more transparent, and the move could help when it comes to submitting evidence in court cases.
Senior superintendent Stephen Yu said officers won't be able to "tamper" with footage that is recorded, explaining that this is because they can only watch what is filmed with a supervisor.
"The colleagues cannot delete the footage. You can't do it, you simply can't do it. We have all the records on who carried the camera beforehand, we do have all the evidence there. So people cannot keep quiet about it," he told the Independent Police Complaints Council (IPCC).
Yu said there's a set of stringent guidelines as to exactly when officers should start recording, for example if there's a need to collect evidence or when a breach of the peace is likely to occur.
The chairman of the IPCC, Anthony Neoh, urged the force to consider getting officers to switch the cameras on if requested by a member of the public, for example, someone subject to a stop and search.
The watchdog's vice chairman, Frankie Yick, added that if officers recorded such searches, this could lead to fewer complaints against police in future.
But Yu replied that frontline officers will decide whether to record events or not, depending on the situation.