The assaults took place over the last year in relation to Church activities or events, said a Toronto Police Service release.
The archdiocese is asking anyone who has information which might help police to call Crime Stoppers at (416) 808-2922 where they may speak up anonymously, or go online at www.222tips.com, or phone (416) 222-TIPS (8477).
The archdiocese has had a program in place to screen parish volunteers since 2001. Phuoc Van, 64, of Toronto, is charged with four counts of sexual assault, two counts of sexual interference and one count of sexual exploitation.