Ottawa Real Estate Investors Organization

Hello everyone! This is my first forum topic as a new member and as far as I have searched, there hasn't been a topic on this one. I could be wrong. Anyways, I purchased an income property in May of this year and one of the tenants has decided to move out. He has requested the interest on his rental deposit for every year that he has lived there. He moved into the unit in 1993. From what I have researched, the previous owner should have paid him the interest (6%) every 12 months from when he moved in. Apparently he didn't do that. Does this mean that I am on the hook for 17 years worth of interest? Any help would be appreciated. Thank you.