Alex Collins had a massive jug of weed and a gun on the floorboards of his crashed Corvette ... and police video obtained by TMZ Sports shows cops making the shocking find and arresting the NFL RB for it.
Collins skidded off the road at around 4:30 a.m. near the Baltimore Ravens' practice facility in Owings Mills, Maryland when he was a member of the team back in March 2019.
In video we obtained ... you can see a cop pulling up to the scene shortly after the crash -- and it's pretty wild.
Collins' pricey ride -- which looks like the Batmobile -- is rammed against some trees and stuck in a snowy ditch ... and Collins appears to be asleep when the officer opens the passenger door.
Collins explains to the cop he had crashed earlier in the morning and was waiting for a tow ... but after Alex had some issues with expired tags, things got dicey for the 25-year-old.
The cop hits him with a ticket, but explains he smells a strong odor of marijuana from the car as well ... and asks him straight-up how much weed he has in the vehicle.
The running back claims he doesn't know ... saying it belonged to his buddy, Tykheem "TJ" Dunaway, who was a passenger in the car earlier but had walked home instead of sticking around.
TJ eventually showed back up to the scene ... and after the cop discovered the jug of weed and a firearm in the car -- he put Collins in cuffs and questioned TJ.
TJ told the cop the weed definitely belonged to Collins ... saying, "It's his. I didn't know it was in the car until it crashed because we were coming from a party."
Eventually, both dudes were arrested for possession of the weed ... while Collins was also booked for having a handgun in his vehicle.
Collins fought the case in court for months ... but in October, he agreed to a plea deal in which he pled guilty to two misdemeanor charges of possession of a handgun and possession of weed.
In exchange, Collins received probation and a fine ... and had his felony charges dropped.
Collins -- who was cut by the Ravens immediately after the arrest -- is still looking for a team this season ... despite being hit with a 3-game suspension by the NFL over the incident.
The former Seattle Seahawks fifth-round pick has 1,509 rushing yards and 14 rushing TDs in his 3-year NFL career.