Firslty, as per the information given by you in the present query, makes it clear that landlord is totally unaware about all these.
Secondly, I advice you to intimate the landlord if possible, and ask them if they can authorise you to file civil suit for injunction against any transaction with respect to the same property.
Thirdly, once you got that then you will be in a position to fight the case on their behalf, and may save the property also from going into the false hands.
Rest, you are free to contact me through Kaanoon for further details.
Good Luck...!