Martin Place siege victim Katrina Dawson was struck by a police bullet when officers shot it out with gunman Man Haron Monis at the Lindt Cafe, the police investigation has reportedly revealed.



Fairfax media reports that multiple police sources have said Dawson, 38, was struck by police fire that was not a direct shot and possibly a ricochet, when Tactical Operations Unit officers stormed the cafe just after 2am on 16 December.



Monis had just shot dead another of the hostages, cafe manager Tori Johnson, at close range, and was killed in the shoot-out.



The circumstances surrounding the 16-hour Martin Place siege is still the subject of a critical incident investigation by the homicide squad.



Dawson’s cause of death will be determined by the NSW Coroner once that investigation is completed.



A police spokeswoman told Fairfax the force would not be commenting on any aspect of the investigation until that process had been completed.