Doubts emerge over timing of Novak Djokovic's positive Covid tests

Questions have arisen over the validity and timing of the positive Covid test results Novak Djokovic used to try to enter Australia before he was deported from the country.

The antivaxx tennis star provided two documents to a federal court in Australia as evidence of his positive status in a bid to avoid rules banning unvaccinated people from entering.

But the serial number on his test from December 16 appears higher than the one on his second test on December 22, the BBC reports.

The code on the first test also appears to be out of sequence with a sample of tests taken in Serbia over the same period, suggesting they were submitted at a later date.

The world number one's application was rejected by Australian authorities, but not on these grounds.

Among the documents submitted to their federal court was one from the acting director of Serbia's official health body which confirmed the dates on the certificates.

The tennis star underwent two tests in his home country and received the results from the Institute of Public Health of Serbia, each with a unique confirmation code.

Data analysed by the BBC shows the confirmation code on the certificates increases chronologically.

The earlier the date the test was carried out, the lower the serial number.

Djokovic's documents appear to be the only ones where the second test has a lower serial number than the first.

His positive test on December 16 has the code 7371999, while the second document has the number 7320919.

Adding to the mystery, it appears the code on the first test suggests it was taken at a later date, between December 25 and December 28.

Djokovic's two tests were carried out in different laboratories, meaning it is possible they could have been issued with different