A Saudi prince and four others were detained on Monday in Lebanon in the largest drug bust in the history of the Beirut airport, a security source said.Saudi prince Abdel Mohsen Bin Walid Bin Abdulaziz and four others were detained by airport security while allegedly "attempting to smuggle about two tons of Captagon pills and some cocaine," a security source told AFP."The smuggling operation is the largest one that has been foiled through the Beirut International Airport," the source said on condition of anonymity.Captagon is the brand name for the amphetamine phenethylline, a synthetic stimulant. The banned drug is consumed mainly in the Middle East and has reportedly been widely used by fighters in Syria.The security source said the drugs had been packed into cases that were waiting to be loaded onto a private plane that was headed to Saudi Arabia.The five Saudi citizens were still in the airport and would be questioned by Lebanon's customs authority, the source added.In April 2014, security forces foiled an attempt to smuggle 15 million capsules of Captagon hidden in shipping containers full of corn from Beirut's port.Lebanon's state news agency also reported Monday's drug bust, saying the private plane was to head to Riyadh and was carrying 40 suitcases full of Captagon.Saudi Arabia's large royal family has had past run-ins with authorities in various countries.Late last month, a Saudi prince was arrested in Los Angeles for allegedly trying to force a woman to perform oral sex on him at a Beverly Hills mansion.But authorities decided not to pursue the charge, citing a lack of evidence. In 2013, a Saudi princess was accused in Los Angeles of enslaving a Kenyan woman as a housemaid, but the charges were also eventually dropped.Earlier this year, a report claimed that the convoy of the son of the Saudi King Salman bin Abdulaziz prompted the stampede that killed hundreds of pilgrims in Mina on Thursday.Citing a report published in a Lebanese daily, Press TV claimed the convoy of Prince Mohammad bin Salman Al Saud played a central role in the deadly crush on the third day of the annual Hajj pilgrimage.Despite the reports, Saudi Arabia’s prince Turki al-Faisal rejected the idea of sharing the administration of the annual Hajj pilgrimage with other Muslim nations, amid calls from Iran for an independent body to manage Hajj.“Oversight of these Holy places and the Hajj is a matter of sovereignty and privilege and service,” the Saudi prince said.Saudi Arabia may run out of financial assets in five years’ time if current spending policies are maintained, the International Monetary Fund has warned.The slump in oil prices has led to Saudi Arabia’s fiscal health coming under pressure, the IMF said. The kingdom will post a budget deficit of more than 20 per cent of gross domestic product this year, amounting to between $100 billion to $150 billion, according to the lender’s estimates.