K A S H R U T . C O M_©

The following kashrus alert is from the Israeli Chief Rabbinate and translated by Google on on December 8, 2014.

In preparation for Chanuka the Israeli government tested olive oils to see if the met the Israeli government standard for olive oils. They listed oils that contained olive oil that meet the standards as well as adulterated and fraudulent olive oils that contained other oils. The fraudulent olive oil could contain Orla, Shmita, non-passover, tevel, colorings/flavorings, emulsifiers. If it costs less than 20 shekels (~$5) per Liter, it's probably too good to be true.
If it's not 100% olive oil, it's not even allowed to say "blended olive oil."
The fraudulent oil is a special concern is those with soy allergies, as soy oil can be the adulterant.
They feel that rabbis should not give a hecksher to olive oil that is not 100% olive oil.