Concern over the ever-increasing stringent emission requirements and rising fuel costs has resulted in closer examination of the control of combustion in internal combustion engines. Natural gas is becoming a viable alternative fuel source, diversifying the transport fuel base, and a fuel potentially offering efficiency and environmental pollution benefits, compared with conventional fuels. Although the potential benefits of the fuel are acknowledged, there are clearly identifiable shortcomings in the control technology applied to the fuel and ignition management system. This paper presents the design of a novel sensing scheme with a fibre optic sensory system capable of monitoring the combustion event in a natural gas engine with minimal invasiveness. The optical sensory system is compared with a pressure sensory signal and used to analyse mass fraction burn and heat release. An integrated ignition controller is presented that enables the ignition angle to be modified, based on the measured optical combustion signal, with a control technique to provide an optimal management of the engine performance.