Phrase Deletion

Dear Experts,

I have deleted the phrase from Active Library ( CUST ), as per standard process, it is then moved to Back Up Library (VPB). I gone to VPB, slected the same phrase and deleted from there even.

But again now i wanted to create in CUST with same Phrase Key, I am getting error that -

Phrase key H02.08500569 is already being used.

Can anybody guide me how to delete the phrase completely from system.

Thanking You !