Images of the hole drilled by thieves into the vault at a Hatton Garden safe deposit company have been released by the Met Police.
Seventy-two safe deposit boxes were opened in a raid at the Hatton Garden Safe Deposit Ltd in central London over the Easter Bank Holiday weekend.
In the vault, discarded safe deposit boxes, power tools including an angle grinder and concrete drills, and crowbars can be seen.
No arrests have been made.
The image shows the hole made using a heavy duty drill, a Hilti DD350.
It measured 50cm (20in) deep, 25cm (10in) high, 45cm (18in) wide and sits 89cm (35in) above the floor.
Police have also released a graphic showing the break-in.
The Met are currently reviewing how they responded to the raid after it emerged an intruder alarm had gone off at the scene of the crime but it decided a response was not required.
Det Supt Craig Turner, head of the Flying Squad, said: "The hours of forensic work and inquiries have been vital in order to ensure we are able to exploit all investigative opportunities to their fullest extent and assist us in identifying those individuals responsible.
"We appreciate this situation has been frustrating for those affected by this crime and thank those individuals for their ongoing patience and support."
There was no sign of forced entry to the outside of the building, the Met said.
Burglars disabled the communal lift on the second floor, then used the lift shaft to climb down into the basement.
The raiders then forced open shutter doors into the basement and bored holes into the vault wall.
All but six of those thought to have been victims of the crime have been contacted, the force said.
The Met Police added:
- Approximately 400 items have been recorded, packaged and recovered, including those for DNA profiling, fingerprints and other evidence
- Digital forensic specialists have been analysing thousands of hours of CCTV footage
- Specialist forensic photographers mapped out the crime scene and used digital techniques to record the inside of the vault.
Scotland Yard said they were alerted to reports of the burglary on 7 April, at 08.10 BST.
Officers are investigating why a call on 3 April at 00:21 BST was given a grade that meant no police response was deemed necessary.
The Met Police have said it is too early to say if the handling of the call would have had an impact on the outcome of the incident.
Earlier this month, CCTV footage emerged which appeared to show the group of burglars behind the raid wearing high visibility jackets and pushing a wheelie bin.
It was claimed the men made two separate visits before leaving on Easter Sunday and making a getaway in a white van.
An appeal will be broadcast on Crimewatch on BBC One on Thursday.