A former Edmonton junior high school principal has been charged with sexual exploitation, and police believe there may be more victims.The Edmonton Police Service said a report was made earlier this year alleging a female youth was sexually assaulted by her teacher multiple times between 2004 and 2008. After that period, the teacher went on to become a principal at another school within the same board..On Wednesday, police arrested 51-year-old Jon Paul David Cooper and charged him with sexual exploitation. He has been released with strict conditions, including a ban from schools, playgrounds, swimming pools, youth shelters and libraries, and from holding any job or volunteer role involving authority over minors.Investigators say they suspect there may be additional complainants and are urging anyone with information to contact police or Crime Stoppers.