Melbourne thief snatches $1m ring from store

A thief has snatched a million dollar ring after smashing a hole in an exclusive central Melbourne jeweller's reinforced window in broad daylight.

The man - dressed in black and wearing a black beanie - used a 1.8-kilogram hammer to smash the hole in the display window of Hardy Brothers Jewellers in Collins Street about 4.40pm (NZT6.40pm) police say.

He grabbed the hand-made 9.1 carat round brilliant cut solitaire engagement ring, billed by Hardy Brothers as the Million Dollar Ring, and fled into an arcade and along nearby Equitable Place.

The store is near a tram stop where, police say, at least 15 passengers would have been waiting at that time on a Sunday afternoon.

Detective Senior Constable Al Brgoc of Melbourne City detectives said he was surprised by the brazen nature of the theft.

"He's given the window a couple of whacks with that and managed to break through a fist-sized hole, reached in not very far, just plucked the ring off its display stand and did the bolt," he told AAP.

"There's no sophistication involved with this. It was the typical smash-grab.

"At 20 to five, even though it's a Sunday, there was still plenty of people around. There is a tram stop nearby that would have had at least 15 or 20 passengers waiting for a tram. It was pretty gutsy."

The hammer, described by police as a "baby sledgehammer, was discovered at the scene.

It was new but the brand name had been scratched from the handle in a bid to obscure where it was bought.

Little evidence remains of the crime on Sunday evening beyond a few shards of glass on the footpath beneath a now empty display case.

John Hardy established Hardy Brothers Jewellers from his rooms in Jamison Street, Sydney, in 1853, soon after his arrival from Nottinghamshire in England.

He opened a shop in Hunter Street in 1855, expanding to Queen Street in Brisbane in 1894 and Collins Street in Melbourne in 1918.

Hardy Brothers holds the royal warrant for silversmithing in Australia.

The Melbourne branch of the jewellery dynasty is located near the corner of Collins and Elizabeth streets in the heart of the Melbourne, close to the city's main shopping areas and financial district.

Det Snr Const Brgoc said detectives would review closed circuit footage and want to speak with anyone who sold a man a small sledgehammer on Sunday.

- AAP