Can a producer who was paid a 'for hire' fee to produce songs try and copyright them as his own?

I paid a producer a large fee to produce my songs on a 'work for hire' basis. He demanded the fee for two reasons; one, to produce the songs in a professional studio; and two, he promised to submit them for placement on TV to his 'contacts.' But upon completion of the recordings he refused to submit them until I gave him 25% of all my publishing and 10% of all my future earning. I happily declined any further involvement with him. It appears that now he has tried to copyright some of the songs so he can place them as his own. Can he do that? I have the songs time stamped in my computer in word docs and demo versions in iTunes. In addition, I filled out the forms online with the US Copyright Office and paid $35 but forgot to send in the hard copy disc of the songs. I have the masters.