Need some Legal Direction.

Need some legal help if anyone can point me to the right direction will be grateful. My Grandfather who was an Omani died a long time ago in a foreign country, his death was reported and therefore the Omani authorities are aware of this. We have aways lived abroad and been citizens of our respected countries. Now I would like to chase up my documents and move back to my home country.  I have his name picture but not his ID or any of his legal documents. I have a land deed that is in his name. Is their anyway to get hold of is ID information?