Seller states didn't sign OF deal, Renter said she did

[Michael Mullins]

Hello Bigger Pockets,

Don't you love the game when you need to find out who is lying to you. 

So I'm in title for a house worth 60k with no loan on it, purchasing for cash for 28k, and I'm hoping to turn it around and sell it to the renter for owner finance. However, renter just sent me a signed lease option back in 2015 with renter and the owners name on it. And the renter is stating that I can buy the property but have to go by the lease option, the seller of the property is stating she didn't sign anything. 

LOL don't you love real estate. I sent the lease option contract over to the title company for them to take a look at it. But what do think I need to do to protect myself here. This is my first time walking into something like this. 

Renter is stating that she only owes 29k left on the loan. So I can't buy the house for 28 that doesn't make sense. 

Any help on the matter would be great.

Thank you,

Michael