Exccessive "Other" Storage

Hi All,

I've recently back up my MacBook Pro onto a couple of hard drives to free up space. However, when I use "About this Mac" to check my storage situation it says that I have nearly 110GB of storage being used by "Other". This is a big problem as my Mac only has 250GB of storage and I've now only got 75GB left.

I can't access the "Other" files in the System Information to delete it and the suggestions online that it's in library don't deem true for my Mac (theres only 5GB in Library)

Any idea on what is taking up so much space that's unspecified? And any ideas on how to delete it?

Below are screen shots of the About This Mac pack and the cleanup page.

Thanks!