The Cadell County Fire Service (CFS) unit has helped fight some of the worst bushfires in South Australia in recent years.

Based in the Riverland, it was the first to respond when last November's Pinery bushfire struck the town of Freeling and provided vital help in fighting the Sampson Flat bushfire at the start of 2015.

But many of the volunteers who make up the brigade are not locals, like in other country units.

They are prisoners serving jail sentences at the Cadell Training Centre.

"I found out that we had a brigade up here and I joined just over a year ago. I thought it was a good way of being able to give back to the community," said one Cadell prisoner who cannot be identified.

"I've been to bushfires, road crash rescues and we've assisted patients [through] helping SA Ambulance.

"It does make you feel good to be able to help people in need - a bit of a feeling of redemption."

The low-security Cadell Training Centre houses 210 prisoners who are completing short sentences or finishing off longer terms for more serious crimes.

The unit was the first to respond when the Pinery bushfire reached Freeling. ( ABC News: Isabel Dayman )

Cadell CFS captain and correctional services worker Chris Coombe said around two dozen prisoners currently volunteered with the unit, which is situated on prison grounds.

"It's one of the longest running programs the Corrections Department has and we basically run the normal brigade out of Cadell, with the two trucks and one four wheel drive," Mr Coombe said.

"We've got 24 guys in our brigade from the [prison] and they're basically the muscle behind our brigade.

"They're the ones that are always here [and] they can be relied upon."

All prisoners are screened for flight risk and cannot leave prison grounds unless they are with a prison officer.

But Mr Coombe said issues with inmates were rare.

"Working with them is not a problem," he said.

"Once we leave the station, it pretty much works like a normal brigade.

"The guys have ownership. They take on that ownership and they take it seriously, so it's good for them."