Help- radio speakers make loud buzzing noise

When engine turned off, radio makes very loud buzzing noise thru speakers(Radio working perfectly otherwise).

Only way to stop it is to pull the fuse.

Any idea's is it a short or earthing issue?

Given that Radio works, surely doesn't need replaced?

many thks
Rooney

Hi its sound like you may have the same problem i had and i'd urgue you to check it out quickly. I had a leak coming in the rear quarter of the vehical basically right above where all the satnav and radio equipment is stored. You sound like you have gotten water in either the big black amp thats fitted at the bottom of the internal boot cupboard or in the silver BM54 radio modual.
If you get this sorted quickly yo maybe able to avoid having to replace all of the components in the cupboard like i did.