Police on the southern highlands have been warned to keep an eye out  for a GOULBURN jail inmate responsible for a carjacking after he  escaped from the minimum security section of the prison yesterday.

Armed robber MARK MAUKAU was discovered missing during lunchtime roll  call.

The 23 year old was serving a two year sentence and was due to be released next year.

Police say he allegedly threatened an elderly couple with a screwdriver outside a laundrette in Goulburn and stole a current model grey MAZDA 3 sedan with NSW registration C-D-Y 82-G.

Mr Maukau is described as being of Maori Pacific Islander appearance, 172 centimetres tall with a medium build.

He is believed to be heading to western Sydney and police are warning members of the public not to approach him as he may be armed and dangerous.

Anyone who sees Mr Maukau or the stolen car  is advised to call Triple Zero.