but we need to be clear there is no legal reason why the support cannot be published. legal reason why the support cannot be published-— doubts have emerged about the timing of a positive covid test novak djokovic used to enter australia, to defend his australian open title. the world men's number one was originally given an exemption from rules which bar unvaccinated people — after he produced evidence of having had covid in december. but the bbc has found a discrepancy on the serial numbers of his test certificates. matt graveling has the details. this was novak djokovic's chance to win his tenth australian open, and with it the most grand slams ever achieved in men's tennis. upon arrival in melbourne onjanuary fifth, and confirming he was unvaccinated, his visa was revoked by the government. the serbian was given