Sheikh Ahmad al-Khalîl, professor at al-Imâm University, Qasîm Branch
The matter depends on whether or not your father had given them possession of the farm. If he only granted them use of the farm, then his inheritors have the right to claim it as part of his estate.
In a case where you do not know whether he gave them possession of the farm or just granted them use of it and there is nothing to indicate either of the two possibilities, we say that basic presumption is your father’s continued ownership of the farm until the time of his death. This is to be legally presumed until evidence to the contrary is produced.
Therefore, in the absence of any evidence showing transfer of ownership, the farm remains part of the man's estate and his inheritors have the right to claim it.
Source: Islam Today