Removing Outstanding financial cost amount on a location with Zero Stock

Hey,

We have numerous pick locations (that are no longer used with this item) which has 0 Physical inventory Inventory but has either a negative or positive Financial cost amount remaining. 

This has occurred with items which were previously assigned the WAQ item group, however we have since run a inventory closing & converted all items to STD.

I thought the inventory closing would have cleared off these balances, however this is not the case. 

Any suggestions how to clear off the balance? 

Thanks

Mel