20/01/2016 12:44 PM AEDT | Updated 28/09/2016 9:55 PM AEST

In-N-Out Burger Pop-Up Sends Sydney Into Frenzy

Fairfax Media

American burger cult favourite In-N-Out sneakily set up a Sydney pop-up on Wednesday, with little notice and zero advertising besides releasing the news to select media outlets just hours beforehand.

The lack of communication was not a factor in its popularity, with a ridiculous line stretching from the Dead Ringer restaurant in Surry Hills, around several corners with hundreds of people reportedly waiting in line from as early as 7am.

Here's that line from another angle:

Reports from the scene were equally as wild, with claims some people had used outsourcing service Airtasker to line up or deliver their burgers and that people who missed out on the sold-out event offering to buy burgers off the lucky ones.

Wristbands were given out to people waiting in line, with wristbands selling out around 11am -- an hour before the pop-up was even supposed to open.

In-N-Out, the American favourite, is so popular in part for its scarcity. It remains a family-run business with locations in only six American states, with most stores in California -- the franchise has resisted expansion across the rest of the United States. It is also famous for its simple menu of only burgers, fries and milkshakes, with a "secret menu" of "animal style" fries and burgers.