Flat roof leak?

[Simba_ali]

Had this small brown water mark at the ceiling wall junction for about 6 months, it's not got worse since and is about 7cm X 1cm.

 

Took some photos today of the top of the flat roof and only think I can see is this...(photo attached) This mark is about 1 meter away from the mark. 

 

Does this look like a hole? I'm not convinced the mark goes all the way through the rubber but can't get better access as it's a 3 story house.