THREE detectives from the Narcotics Bureau were arrested by the Independent Commission Against Corruption (ICAC) last week in the latest of a growing number of operations against the disciplined services.
The officers were picked up last Thursday and were officially arrested early on Friday. All three have since been released on bail.
Other Narcotics Bureau detectives are believed to have been questioned by the anti-graft force as part of the investigation, which one detective believed was linked to an 'informer'.
A team of ICAC officers searched the detectives' offices in May House at police headquarters last Friday morning.
It is believed to be the first time since the 1980s that ICAC agents have searched offices in police headquarters as part of an official investigation.
One detective said the arrests, raid and planned questioning of other officers had already caused a drop in morale in the Narcotics Bureau and could lead to increased tension between the two services.
One of the officers arrested was identified by a colleague as Detective Senior Inspector Ho Chi-kit, who is in charge of an operational team in the drug squad.