We present a comprehensive investigation of laser induced damage in silicon by implementing a methodology allowing the identification and the localization of the defects. PL analyses combined with TEM reveals that laser annealed samples reveal the presence of Carbon and Oxygen related defects, in the form of C-lines and G-lines (including the associated G satellite lines). Additional Oxygen related defects (Si-O-Si complexes) were revealed by FTIR analysis. Based on SIMS analyses combined with chemical etch, it is found that the optical defects observed in laser annealed samples originate from the oxygen atoms and carbon impurities contained in the surface native oxide from which they are released and subsequently diffuse into the substrate during anneal down to the liquid/solid interface.