A person of poor origins that has no qualms about stealing.
It is in no way used as a racist term as it can be used to describe anybody.
It was brought to the limelight by Danny Dyer in The Business ("They're thieving cunts, Moroccans, it's in their blood." and ".....cos, like Moroccans, South Londoners are thieving cunts)
Dave: "Dude, wheres my watch?"
Kev: "Um.... I.. er... Stole it!?! "
Dave: "What the fuck!! Kev, you are such a fucking Morrocan!"