Multiple copies of same Media after 2010 - 2012 upgrade

Hi all,

So after upgrading from BE 2010 -2012 I have ended up with multiple copies of some of my tapes.

For example, I have a tape named TWS053L4.  If I look at 'All media' I can see it 3 entries for it.  They were in different Media Sets but I have put them all in the media set I want them to be.

One of the entries shows the location as my Robotic Library, so I believe this is the 'correct' one, but hjow can I safely get rid of the duplicate entries?