'Wahlburgers' Star Henry 'Nacho' Laun Dead at 54

Henry "Nacho" Laun -- the extreme eating star of "Wahlburgers" and one of Mark Wahlberg's OG entourage members -- has died after suffering a medical emergency a couple weeks ago ... TMZ has learned.

Sources close to Laun tell us he passed away Tuesday at a Massachusetts hospital.

We broke the story ... the reality star was on a road trip from Boston to Cape Cod in mid-May when he was found unconscious in his vehicle at a gas station.

Our sources say it's still unclear what caused his medical emergency, but after Laun was transported to the hospital his condition did not improve. We're told he was unresponsive and placed on life support because he couldn't breathe on his own.

We're also told family and friends had a glimmer of hope, as Nacho was showing signs of recovery in recent days -- but he took a final turn for the worse.

Laun was a fan favorite on "Wahlburgers" known for never shying away from an eating challenge and of course, for being Mark's buddy.

His attorney and friends have organized a GoFundMe to help with funeral costs.

Laun's attorney, James Neyman, declined to comment.

Laun was 54.