The Cape Winelands District Municipality says the fire at Brandvlei has returned and is burning out of control.
The municipality said firefighters from the Breede Valley Municipality also responded to the scene, saying that although the blaze was on the grounds of the Brandvlei Prison, the safety of prisoners and the facilities were not compromised.
"There is currently no threat to the safety of the prison, its staff or prisoners. The facility is fully aware of developments and is being kept informed by the Incident Commander," the municipality said on Monday evening.