The document in question showed that Novak Djokovic tested positive for COVID-19 on December 16.
German news magazine Der Spiegel said earlier this week the QR code for the test showed a negative result when first scanned but subsequently a positive one, and questioned when the test was actually taken.
Gojkovic, a member of the Serbian health ministry's COVID-19 crisis-fighting team, said he regretted Djokovic had not been vaccinated against COVID-19 but would defend his choice.
Although Djokovic has publicly opposed compulsory vaccination, he has not campaigned against vaccination in general.
