Abd al-Muhsen bin Walid bin Abd al-Aziz Al Saud was detained on Monday in Beirut’s Rafik Hariri International Airport.
The prince was about to conduct a flight on his private plane to Saudi Arabia.
Lebanese TV station Al Mayadeen also said that 40 packages of drugs, weighing 2 tons in total, were confiscated.
The prince was arrested and taken in for questioning. According to Press TV they were charged with attempting to smuggle pills of captagon, an amphetamine allegedly widely used among fighters in the Middle East.
Captagon is a brand name for the widely used amphetamine phenethylline.
It is the drug of choice for front-line fighters on both sides in the Syrian war, allowing a heightened state of alertness.
It is unclear where the pills allegedly found in Beirut were ultimately to be sold, although the plane was said to be heading back to Saudi Arabia