Investigators in Toronto say they've charged a man who allegedly impersonated a police officer to sexually assault a woman.

Police say a man approached a 36-year-old woman on the street around noon on Sept. 11, showed her an object resembling a police badge and then sexually assaulted her.

They say a 55-year-old Toronto man was arrested on Wednesday and charged with sexual assault and impersonating a peace officer.

Police say they are concerned there may be other alleged victims.

They say the accused has two distinctive tattoos: a mermaid on his left biceps, and a large multi-coloured star with a human eye in the middle of his right forearm.

Anyone with information is asked to contact police.