It's often a big mess who is owner to real estates, which don't have titles.
1. It can be not cleared inheritances, sometimes in more than one step. So sometimes come a third cousin or such and claim they haven't got their part of inheriance/sale, many years later..
2. SCAM risk. ANYONE can pay tax for a real estate and then use that to fool buyer they are owner WITHOUT any false document !!!
..
I DON'T know any much about how to solve such mess, but how to avoid it
=Get title. Extrajudical process can be needed first to make clear who are hiers, when it's inherited.
Actualy Titling often RAISE the value much more than it cost to do it. I know some cost only 2000- 3000p to title.
Depending of type, but some you get approved just by applying and pay the fee, IF you have had it within the family and paid tax at least 10 years. Some types demand your family have USED the land enough many years to get it.
How did you GET the land? Can you prove it?
If so you can just try to sell it anyway, because you have the tax prooves too.
What does your relative say, when you show it's other land he has paid tax for? And sold TWICE !
And what does he say about he risk prison for selling land he don't own (if he don't solve the mess) ?