Two more officers from a high-profile Hamilton police ACTION unit under investigation for allegedly writing false tickets have been placed on administrative duty.

This brings to five the total number of officers removed from active duty, say police sources not authorized to speak on the record. Three officers were placed on administrative duty in December.

Two more investigators have also been added to the internal investigation team, being led by central division detectives, the sources say. This means four officers are working on the growing case.

The five officers under investigation are to remain on administrative duty throughout the rest of the internal probe, which began after provincial offence notice books were found in a box destined for the shredder in late September. It's alleged the tickets were logged with the courts, but never handed out.

Police sources say it's believed many of the people targeted are vulnerable people known to police who have no idea tickets were registered against them.

The officers are part of ACTION Team One, one of five teams in the high-profile unit initiated by Chief Glenn De Caire to patrol high-need areas on foot or bike. Each team has six officers and one sergeant.

Hamilton police have declined to comment further until the investigation is complete.

In a previous statement, spokesperson Catherine Martin said the "matter is being taken very seriously, will be investigated thoroughly, and appropriate steps will be taken."

She also said the ACTION strategy is "a proven community-based initiative based on sound research … (that) has resulted in a city-wide reduction in crime."

News of the investigation sparked a call from Mountain councillor and police board member Terry Whitehead for an outside service, such as the OPP, to lead the investigation. That issue has not been publicly addressed by police.