Jarret Stoll Arrest -- Busted Smuggling 8-Ball ... In Board Shorts

NHL star Jarret Stoll tried to smuggle an 8-ball of cocaine and 8 grams of Molly into a Vegas pool party ... by hiding them in his board shorts ... this according to the police report obtained by TMZ Sports.

The L.A. Kings player was busted around 4:30 PM on Friday while going through the security area -- that EVERYONE goes through -- on the way in to the Wet Republic pool party at the MGM Grand.

Despite the sign CLEARLY warning people that they will be patted down on the way inside, Stoll took his chances ... and a Wet Republic security guard found a pink baggie with white powder and numerous "gel-caps" with an off-white powder inside consistent with the drug "Molly."

According to the police report ... when asked if the powder inside the baggie was coke, Stoll said, "Yes."

Cops say Stoll had 3.3 grams of coke ... and 8.1 grams of Molly.

Stoll -- who's famously dating "Dancing with the Stars" co-host Erin Andrews -- was transported to a nearby jail ... where he was booked for drug possession.

He was eventually released after posting $5,000 bond.