A small amount of marijuana was discovered on a passenger on Rihanna’s tour bus after 10 of them were stopped and searched while crossing the US border with Canada but the singer was not on board.

Rihanna’s tour buses were allegedly stopped and searched for drugs. The ‘Stay’ singer – who recently kicked off her ‘Diamonds’ world tour – was not on any of the buses when they were reportedly stopped at the border between Michigan and Canada but a “small amount” of marijuana was discovered on an unidentified passenger.

A law enforcement source told media that a total number of ten buses were stopped at the Ambassador Bridge, which separates Windsor, Canada and Detroit, and inspectors initiated a secondary bus-to-bus search after an officer smelt the drug on one of the buses. A sniffer dog was brought on board and detected drugs on one passenger, who was then searched and a small amount of marijuana was discovered.

He was reportedly cited with a civil penalty.

The 24-year-old star resumed her tour last Thursday (14.03.13) after being forced to cancel two shows in Boston and Baltimore after falling ill with laryngitis immediately after the first show of the tour in New York state and tweeted she was “embarrassed” about it. Rihanna wrote: “BOSTON this is the hardest thing for me to deal with! I feel like we’ve been waiting on this day forever, and I’m hurt that I let you down (sic).

“I hate disappointing people that never ever let me down!! I’m so embarrassed about this! Thank you for your prayers and well wishes! (sic).” – Femalefirst