4:05 PM PT -- A source close to Clark tells us ... the NFL star claims the weapon belongs to a member of his security team. We're told attorney Alex Spiro will represent him moving forward in the case.
NFL star pass rusher Frank Clark -- one of the best defensive players in the league -- was arrested Sunday after cops say he had an uzi in his Lambo SUV ... TMZ Sports has learned.
Law enforcement sources tell us Clark was pulled over for a routine traffic stop Sunday evening in Los Angeles ... when cops say they noticed an open duffle bag in his ride.
Our sources say officers saw the gun inside the bag ... and arrested the 28-year-old for felony illegal possession of a firearm.
The Kansas City Chiefs superstar is still behind bars in the Los Angeles area, jail records show.
According to the records, Clark -- listed at 6'3", 255 pounds -- was arrested at 9:20 p.m. ... and was booked into jail hours later at 9:28 a.m. Monday.
We've reached out to Clark and the Chiefs for comment ... but so far, no word back yet.
Clark was a key piece in the Chiefs' runs to the Super Bowls the last two years ... after being traded from Seattle to Kansas City before the 2019 season, Clark logged 14 sacks in 26 starts and was great in postseason play too.
In fact, Clark was so good for the Chiefs since joining the team ... he was selected to the Pro Bowl in each of his 2 seasons on the squad.
Of course, this is not Clark's first brush with legal trouble ... you'll recall, he was arrested in 2014 after being accused of domestic violence -- and was kicked off the Univ. of Michigan football team over it all.
Clark eventually struck a deal with prosecutors in that case, agreeing to plead guilty to a lesser charge of misdemeanor disorderly conduct.
Clark is currently in the middle of a 5-year, $104 MILLION contract with the Chiefs.