BELGRADE, Jan 14 World number one Novak Djokovic in trouble with participation in the Australian Open tournament, had official confirmation from a medical institution in Serbia that he had COVID-19, Zoran Gojkovic, a spokesman for the national crisis headquarters for infectious diseases, said. The Federal Court of Australia will consider the case of canceling the visa of Serbian tennis player Novak Djokovic on Saturday. Before the meeting, Djokovic must appear for a conversation with representatives of the Australian immigration authorities. Until then, as previously reported, he will not be detained. «Novak Djokovic had a valid document issued by Serbian medical institutions confirming that he was positive for COVID-19,» Dr. Gojkovic said at a briefing after the crisis headquarters meeting on Friday .Earlier, the issue of Djokovic's stay in Australia, where he should take part in the Australian Open championship, was considered by the Federal District Court. According to his decision, the deprivation of Djokovic's visa upon arrival in the country on the night of January 6 was unreasonable. However, on Friday, Australian Immigration Minister Alex Hawke decided to cancel the visa again.