deleted photos still take up storage

I have deleted all my pics including from recently deleted and i have 45GB in icloud but still my photos are taking up a lot of space even though there is nothing in the photo album. Please help urgent issue!!

I had this problem for a long time with my 16gb iPhone. After a lot of looking I discovered iExplore and this tip:

http://iexplorer-support.macroplant.com/customer/portal/articles/1325738-how-to-delete-all-photos-from-an-iphone-or-ipad

Essentially, Photos caches lots of files and due iOS bugs, the caches don't always get cleared up.

I used the solution on the above page and cleared up 2GB of space.

I have resolved my problem using iExplorer (mentioned by @billyork23). In my case, it is the thumbnail data of old photos. You can locate it under:

Media/PhotoData/Thumbnails

and delete all .ithumb files. It saves me 1.5GB.

P.S. The iExplorer does not require jailbreak or anything.