Andy Murray says it is "positive" that Novak Djokovic has been released from detention in Australia but the Serb still has "a few questions" to answer.

But Australian border officials are investigating whether his travel entry form included a false declaration.

"It's positive that he's not in detention any more," said Murray.

"There are still a few questions that need to be answered around the isolation, which I'm sure we'll hear from him in the next few days."

Djokovic's travel declaration form, which all visitors have to complete three to seven days before arrival, stated he did not travel in the 14 days before his flight to Australia.

However, social media posts appear to show him in both Serbian capital Belgrade and Spain during that period.

Australia's immigration minister still has powers to re-cancel the visa and deport the unvaccinated player.

"He won in court, which is good," added Murray, who said the situation was "really not good for tennis at all" last week.

"It looks like he's going to be able to play and compete in the Australian Open - we do want the best players there, but there are still a few questions to be answered.

"Until that happens, it is tough to give a definitive opinion on everything."

Murray, 34, said the drama around Djokovic was "frustrating" as he would rather "talk about my tennis".

The former world number one was speaking after he beat Norway's Viktor Durasovic 6-3 6-1 in round one of the Sydney Tennis Classic.

Britain's Murray will face Georgian second seed Nikoloz Basilashvili in the second round.

Three-time Grand Slam champion Murray has accepted a wildcard for the Australian Open in what will be his first appearance there since his emotional first-round exit in 2019.

Murray said he could be forced to retire through injury then, but made a comeback after having surgery on his hip for the second time.

"It is really nice to get my range and hopefully I can carry that through [to the Australian Open]," said Murray, who lost in the first round of the Melbourne Summer Series.

"I believe I can have a good run there and who knows, if I can find a bit of form and the draw opens up?"