Trumot and Maasrot from a Gentile's Oil

I received a bottle of olive oil from an Arab (he grew the olives and prepared the oil). Do I need to separate trumot and maasrot?

Shalom!
If indeed he grew and prepared it, the oil is exempt from trumot and maasrot.
However, one must verify oil’s true origin, as often there are forgeries, and it is possible that other oils that do require the separation of trumot and maasrot are mixed in.
In addition, if there is a possibility that something was added to the oil, it is forbidden to eat it, since the substances that were added to it might be prohibited.