SHAFAQNA – The Grand Ayatollah Khamenei answered a question about lying and deceit in trade with non-Muslims.
Question: What is the ruling regarding cheating, lying and deceit to attain more profit or more scientific benefit (if they are not aware) in trade with non-Muslims?
The Grand Ayatollah Khamenei: Lying, deceit and cheating are not allowed in trade even with Non-Muslims.
Source: PERSIAN SHAFAQNA