Disco 2 Air compressor

I have a 2001 disco, and I have noticed that when I park up, and switcht off, the air compressor is still running. The only way to stop this is to remove the fuse under the bonnet. When i put the the fuse back next day it was fine. ..Whats going on, it has happened again today.
Is it safe to drive with the fuse removed ?
There seems to be no problems with the air suspension

It will self level for something like two min after switch off. This includes lifting up (comp on) and dropping down (hissing noise). If its only on for a short period i would say its normal, if its none stop you might have an air leak or other fault. Does it drop overnight?

Hi
There is no drop overnight,this morning I put the fuse back in and the compressor started up with out the ignition on.
I moved the relay with a little wiggle and it stopped!.
I have used the Disco this evening , and raised / lowered the suspension, all works ok, and the pump turns off with the ignition....
perhaps its the relay?????
regards
Ray