starter will not stop turning engine over even with no key in ignition.

I had problems intermittently with it not wanting to turn over unless I bumped it a few times then it would start and run normally. now the starter will not disengage even though I have turned the car off and taken out the key. To stop it I must disconnect the battery, but as soon as I reconnect the battery the starter begins to turn the engine over. I have removed the ignition fuse and starter relay to no avail.