CFB Petawawa Corporal Derrick Gallagher, 31, is now facing 18 new charges including eight counts of sexual assault, nine counts of voyeurism and one count of assault.
Gallagher was arrested March 31, and had since been charged with eight counts of sexual assault and two counts of voyeurism.
Police haven't made clear what the voyeurism charges are for but under the Criminal Code of Canada, it can include video taping "if the observation or recording is done for a sexual purpose."
Police believe there are several dozen more women out there who are potential victims and don't even know it.
They're asking anyone who may have come in contact with Gallagher since January 2007 to come forward.
"We do need these people to come forward, we do need to speak to them, we do have health concerns that we need to share with these people," said OPP Sgt. Kristine Rae.
Police said the victims may have unknowingly contracted a sexually transmitted disease.
Gallagher appeared in court by video Thursday and is due back before a judge on April 24.