'America's Next Top Model' Contestant -- Robbed at Gunpoint in Broad Daylight

Former "America's Next Top Model" contestant Don Benjamin hit up an art supply store in the middle of an afternoon, and ended up getting jacked for $3,000 ... at gunpoint.

A rep for Benjamin -- who was on Cycle 20 of the show in 2013 -- tells TMZ he was walking into a store in downtown L.A. on Wednesday around 3:00 PM ... when the attacker put a gun to his head.

Benjamin immediately forked over 3 grand in cash and the gunman bolted with another guy in their getaway car. He reported the incident to police, but was unable to give them a suspect description.

Law enforcement sources tell TMZ they are investigating, but so far ... no arrests.