3817497 - Error: This Item Code is already used by other item that's been deleted

Whilst trying to modify an existing List Item Code within a List and clicking Save the error message: "This Item Code is already used by other item that's been deleted" appears. How do I fix this?

When trying to modify an existing List Item Code within a List I get the error "This Item Code is already used by other item that's been deleted" When an admin is trying to add or modify the ITEM CODE for a Item Name in list error"This Item Code is already used by other item that's been deleted" is received. , KBA , CON-EXP-ADM-LIS , List Management , CON-CA-TLS-IEM , Import / Extract Monitor , Problem