BUDVA, Montenegro (AP)Tennis star Novak Djokovic received honors at a small Adriatic Sea resort in Montenegro on Friday even as doubts re-emerged about the positive COVID-19 test he used to try to compete in the Australian Open.

The BBC on Friday reported discrepancies in the serial numbers of tests Serbian authorities administered to Djokovic in the days prior to his trip to Australia, suggesting possible irregularities in the way they were issued.

Djokovic’s media team and the Institute of Public Health in Serbia did not immediately respond to requests for comment from the Associated Press. Senior Serbian health officials have previously said that Djokovic’s test was valid and issued by a relevant institution.

Djokovic was deported from Australia and barred from playing in the Australian Open earlier this month after a 11-day visa saga on the eve of the tournament because he failed to meet Australia’s strict COVID-19 vaccination requirements.

To enter Australia, Djokovic submitted a positive COVID test issued in Serbia from Dec. 16 for a visa exemption on the grounds that he had contracted COVID-19 prior to the tournament.

The 34-year-old player is not vaccinated and the Australian government later decided to cancel his visa and deport Djokovic, saying his presence in Australia could stir anti-vaccination sentiments.

Djokovic has said he would make no public comments until the end of the Australia Open tournament.

On Friday, several hundred people cheered outside the municipal building in the small Adriatic town of Budva as Djokovic arrived to receive a plaque declaring him an honorary citizen of the town.

Top local official Marko Carevic also presented Djokovic with an Orthodox Christian icon, expressing gratitude for helping ”preserve the Serbian people and the Serbian church in Montenegro.”

Djokovic is adored in his native Serbia and among the Serbs in neighboring Montenegro, a small nation of some 620,000 people. Since he returned home, Djokovic was seen visiting churches and attending liturgies in both Serbia and Montenegro.

A video posted on social networks showed a mask-less Djokovic taking communion from Serbian Patriarch Porfirije on an Orthodox Christian holiday, using the same spoon along with other faithful at a church in Belgrade.