Unmarried renting two room apartment law (Abu Dhabi)

Hi all!
I've been living here two years now in company accommodation. I recently got a promotion and with that the opportunity to get a place of my own. I found a wonderful two bedroom apartment on Reem island and I'm just about to finalise the lease but a problem has arose with the fact that I'm not married. In order for me to proceed I need to produce a copy of my mother's passport. Has anyone come across this and what exactly happens with my mother's information? I understand it could be something to do with subletting or the fact that unmarried people are not allowed to live together. I don't plan on letting the room out as I could really do with the extra storage space!!