The NYPD is hunting a trio of armed jewelry thieves wanted for a brazen daylight diamond heist.

Police have released footage of the alleged robbery at Avianne & Co, a store in Midtown Manhattan鈥檚 Diamond District favoured by famous rappers including Nicki Minaj, Justin Bieber and Lil Wayne.

The NYPD said the incident happened on Sunday August 25 at around midday.

鈥淭he suspects displayed firearms and tied up four individuals before taking an undetermined amount of jewelry,鈥 the .

But a source told the the thieves made off with jewelry worth US$4 million (CA$5.3 million).

The shocking footage from inside the store shows one employee forced to lie on the ground at gunpoint as the thieves gather their loot.

One of the bandits, posing as a customer wearing a blue suit and grey fedora over long thick braids, reaches down between his legs and raises a silver semiautomatic handgun and racks the slide, before pointing the weapon at the worker on the other side of the desk.

The video shows more two accomplices, one who also brandished a pistol and had long braids under a bandanna, with a police source telling both men appeared to be wearing wigs.

The third man was wearing a bucket hat and carrying a duffel bag.

The three thieves didn鈥檛 bother to cover their faces and are clearly visible on the surveillance footage.

They struck on a Sunday when most stores in the district were closed and there was a smaller police presence.

The raiders forced four employees, one as young as 15, to lie down in the back room before duct-taping and zip-tying them, . One of the staff was forced to open two safes and multiple display cases.

Surveillance footage from a neighbouring store showed the three thieves heading east after the robbery wearing Avianne & Co backpacks stuffed with stolen loot.

No one was injured during the heist.