What is the religious ruling on a tenant demanding thirty thousand Egyptian pounds to relinquish an old lease contract, and is the landlord committing a sin by paying this amount, and what is the ruling on old, unjust lease contracts in the present time?

The perpetual old rental contract is Islamically void. It must be annulled, and the property returned to the owner, along with payment of the fair market rent for the period of use. The tenant's demand for money in exchange for returning the property to the owner is forbidden injustice. However, there is no sin upon the owner if he pays this amount if he finds no other way to reclaim his right, and the sin falls upon the unjust tenant who wrongfully takes the money.