Andy Murray has blamed lax coronavirus protocols at the Lawn Tennis Association's flagship National Tennis Centre for the positive test that forced him to miss the Australian Open.

The former world number one had to isolate after testing positive on January 11 and was unable to take up his seat on the charter flight organised by Tennis Australia.

He still hoped a solution could be found to allow him to compete in Melbourne but accepted defeat after being told he would have to endure two weeks of hard quarantine.

There was a distinct irony that Murray chose to pull out of the tournament he had entered in the United States because of fears of contracting the virus, practising at the NTC in Roehampton instead.

The 33-year-old considered himself ultra cautious and has no doubt that he picked up the illness, which left him feeling under the weather for a couple of days, while training.

Murray said: "I stuck to all of the protocols that were in place. I didn't leave my house or the NTC for the 10 weeks of training. I was very careful because it's not just for tennis reasons."

Murray passed the virus on to his family, with wife Kim testing positive followed by his three young children, while another member of the Scot's wider family became very ill after also catching it.

He said: "I was p***ed off that I missed the tournament and wasn't able to go to Australia from a personal perspective but then the wider, more important point is that it's not just about a tennis tournament when I am going back and giving the virus to all of my family and infecting them. I care about that a lot."

Murray highlighted notable differences between the environment at the NTC once it was allowed to reopen following the first lockdown and the situation after Christmas, when he felt other users of the centre were not showing the same respect for the rules as he was.

The Scot's positive test was part of a small outbreak that also took in an LTA doctor and young British player Paul Jubb.

"When we went to the NTC in April last year, if there are six indoor courts, you could only practise on one, three and five," said the three-time grand slam champion.

"There wasn't any testing at that time but the gym was closed and it was restricted access. It was very different.

Murray will begin his season on Monday in the much-less-celebrated surroundings of a second-tier Challenger event in Biella, Italy.

The Scot is desperate to get back into action after a much-disrupted comeback from hip surgery two years ago and is feeling fit and ready following a strong training block.

The sting of missing out on another grand slam tournament remains, and he feels complaints from players in quarantine in Australia did not help his cause for an exception to be made.

He said: "I still am gutted about it. When I'm sitting in my hotel room here when I'm obviously healthy and fit and ready to play and compete, seeing the tournaments going on over there is tough, because I'd prepared really, really well, it had probably been the best two or three months' training that I had done in the last few years.

"Even after the positive test, it seemed like everything was going quite well. I think the carry-on from some of the players over in Australia didn't really help my situation much."