Andy Murray has spoken of his anger at missing next week's Australian Open because he caught Covid-19, pointing the finger at the culture inside the National Tennis Centre over Christmas.

The Scot says "tonnes of people were in the gym" and thinks too many were allowed to use the player facilities.

The LTA said "stringent and appropriate restrictions" had been applied.

As a result of catching coronavirus, Murray was not allowed to travel to Melbourne on a chartered flight as planned and was then unable to find a "workable quarantine" to play at the Grand Slam after recovering.

Instead the former world number one will play in Italy next week on the ATP Challenger Tour.

"When we went to the NTC in April, if there are six indoor courts, you could only practise on one, three and five. There wasn't any testing at that time, but the gym was closed and it was restricted access," said Murray.

"Whereas after Christmas you have an indoor venue where they are using all six courts, there were tonnes of people in the gym, and it was just totally different.

"Now it's kind of back to what it was in April, which is good. It's a completely different building. All the communal areas are severely restricted, like the lunch hall; there's probably seven or eight seats maximum in there now, before there would have been 30 to 40.

"But the reality is that it happened too late because there were quite a number of cases between Christmas, New Year and the players going off to Australia."

Others have privately expressed reservations about the numbers allowed into the player lounge, and the lack of social distancing and mask wearing by some.

British number one Dan Evans trained at the NTC before flying to the Australian Open and suggested attitudes there to the virus had "slackened".

"I was pretty nervous the last few days because we knew the virus was there. But I got out unscathed," he said.

"If I was being a bit harsh, without being rude to some players in there, they probably shouldn't have been in there. I don't think they were really of much importance.

"The importance should have been on getting healthy people to the Australian Open and there were probably people in there who weren't preparing for tournaments. Just because there wasn't stuff on, they were maybe using the centre just to practise, to get out."

In response, the LTA pointed out the impossibility of eradicating all risk with the virus so widespread and said it was impossible to "police every part of the building continuously".

"We have consistently applied the stringent and appropriate restrictions, testing and other protocols for elite training centres in line with government guidance," the LTA said in a statement.

"We have worked closely with Public Health England in order to keep the centre open since April for both training and as a host venue for over 1000 competitive matches across 17 tournaments on site.

"Our protocols are regularly communicated to everyone using the venue and we expect them to be adhered to in the player lounge and all other areas of the building."

The first sign of sickness Murray had was when he developed a slightly dry throat a few days before his flight to Melbourne.

What started as a joke among his team became more serious when he woke up at 3am the following morning with an aching body and sore head.

"Three hours later I had the message through on my phone that I had tested positive," he recalled.

"For two days, I was pretty ill. I basically stayed in my room for five or six days, because I didn't want my family to get it, if possible.

"But then five to six days later my wife tested positive, then a few days after that the kids tested positive, so the whole family got it in the end."

With Murray and his family now fully recovered, he has travelled to the Italian city of Biella where he will play in the Challenger tournament. The top seed faces Germany's Maximilian Marterer on Monday.