Police initially charged a suspect in May with four counts of indecent assault on a female related to alleged incidents between 1972 and 1975.
On Tuesday, police said the same suspect was charged with one count of indecent assault on a female and another count of gross indecency stemming from alleged incidents in Ottawa between 1972 and 1973.
They said the new charges were based on claims made by two additional alleged victims.
Ottawa police say all of the alleged incidents occurred in the Bells Corners area of the city where the suspect was living at the time and say they are concerned there may be more alleged victims. Police say Maynard Hamilton of Ottawa will appear in court on Oct. 25.