Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
We advise you to contact the authority that issued this check, most probably they will provide the details about the owner of the check and thus you may handover the check to the right person.
If you cannot find the address of the person in this case you have to advertise about this check, not giving the details, in media, or putting notice on the public places such as mosques, markets, hospitals, etc. If one comes to you and give you all the correct details then you have to give it to him.
If you did not find the real owner in this case we advise you to keep the check, probably the owner has registered a complained to the bank about the loss of his check and in this case if you want withdraw the amount you may be charged with forgery.
Allah knows best.