[3] If the accused had been identified at an identification parade by the witness, Simon Liew, without that witness having been first afforded the opportunity of seeing the accused, we feel that there might well be sufficient evidence to justify the conviction. The onus on the prosecution when the evidence is of a circumstantial nature is a very heavy one and that evidence must point irresistably to the conclusion of the guilt of the accused. If there are gaps in it then it is not sufficient. The fact that Simon Liew was invited to the police station to identify the accused not only in our opinion vitiates the subsequent identification at the parade, but raises the most grave doubts as to the whole of his evidence