Inside the new wing of the Goulburn high security prison

One of Australia's highest security prisons has been given an upgrade.

A new high-security wing of Goulburn's High Risk Management Correctional Centre has been refurbished with new technology to monitor some of Australia's most violent criminals.

The wing houses criminals on terror charges and other extreme crimes.

READ MORE: Wild weather to lash three Australian states

"This is the most secure facility and probably in the Southern Hemisphere," Minister Anthony Roberts said.

There are now 75 beds in the wing.

"Increasing the operational capacity of Supermax from 45 to 75 beds allows Corrective Services NSW to separate convicted terrorists from other inmates, thereby reducing the risk of radicalisation within the prison system," Mr Roberts said.

The upgrade is part of a wider $47 million NSW Government investment in countering terrorism and violent extremism.

"The contemporary refurb makes it safer for staff and safer for inmates as well," Governor Wayne Taylor said.

READ MORE: She died from a snakebite. But the real killer was her husband

The site features a fully integrated security management system across the entire prison, with a new control room and equipment.

The upgrade included new CCTV facilities, telephone and audio monitoring, an X-ray machine and walk through metal detector.

It also has state of the art body scans that replace most strip searches.

Phone, family and counselling rooms are also electronically monitored.

The exercise yards are enclosed with mesh which prevents drones from dropping in contraband.

READ MORE: New clue found in search for William Tyrrell

Each prisoner is monitored by three guards and each cell has a private exercise yard to prevent interaction between inmates.

"Many of the prisoners we have are not a danger to society but a danger to the prisoners," Mr Roberts said.