destroying PGP private keys (Re: Home Office response on Burden of Proof)

[Pete Bentley]

At Sun, 08 Aug 1999 00:28:19 BST, Adam Back writes:
>To destroy a private key you remove it from your key ring (pgp -kr)
>and wipe the backup keyring (pgp -w secring.bak).  

And get rid of all copies of it on backup tapes...

Which raises a question. Say I get served with a decryption notice for
messages encrypted with a PGP public key, and I claim that the
corresponding private key and all its backups have been
destroyed. Would the authorities have to take my word on the backup
issue, or would they be entitled to seize all backup tapes to look for
the key (allowing them to go on a fishing expedition for any other
file).

Pete.