Andy Murray finds it "hypocritical" that tennis authorities are trying to stamp out match-fixing run by gambling syndicates but have partnered with a major gambling company that is now advertising on the Australian Open's show courts.

The two issues are separate but have collided at this year's Australian Open, where tennis was overshadowed for a second day Tuesday by allegations that match-fixing has gone unchecked in tennis.

The controversy ignited Monday when the BBC and Buzzfeed News published reports alleging that the sport's highest authorities had ignored evidence of match-fixing involving 16 players who had been ranked in the top 50 over the past decade. The report said that half of those players were at this year's Australian Open but did not name names.

The governing bodies for tennis have presented a unified front in rejecting the claims, and highlighted the fact that five players and an official had received life bans after investigations from the Tennis Integrity Unit which was set up in 2008.

No. 2-ranked Murray and other top players, including Roger Federer and Novak Djokovic, say authorities could be doing more to combat the problem. The players said they have known the issue existed but they doubt any top players have been involved.

Murray said the sport was sending mixed messages by allowing betting company William Hill to become one of the Australian Open's sponsor's this year and advertise on the tournament's three main show courts.

For the first time at Melbourne Park, electronic advertising boards at Rod Laver Arena, Margaret Court Arena and Hisense Arena display the name "William Hill" during breaks in play.

'Positive topspin'

"I'm not really pro that," Murray, a four-time finalist in Melbourne said Tuesday, after advancing to the second round.

"I think it's a little bit hypocritical," Murray added. "You know, because I don't believe the players are allowed to be sponsored by betting companies, but the tournaments are. I don't really understand how it all works. I think it's a bit strange."

A day earlier, No. 1-ranked Djokovic called it "borderline."

"It's a fine line. Honestly, it's on a borderline, I would say," Djokovic said. "Whether you want to have betting companies involved in the big tournaments in our sport or not, it's hard to say what's right and what's wrong."

Tennis officials defended the partnership with gambling sponsors and provided an explanation that one Australian paper, The Age, called "positive topspin."

ATP Chairman Chris Kermode said that betting on sports was "a legal pastime" — not to be confused with corrupt forms of gambling like match-fixing.

"The distinction to make is that betting itself is not an illegal pastime and many people do bet on sport. What we are talking about is corruption," he told a news conference Monday called to reject claims that any evidence on match-fixing had been suppressed or gone unchecked.

Kermode added that legitimate betting agencies could even help tennis authorities to spot corruption, since stamping out illegal gambling benefits them too.

Fernando Verdasco joined the conversation, after staging the tournament's biggest upset so far by beating Rafael Nadal in a first-round five-setter Tuesday.

The No. 45-ranked Verdasco was still basking in his victory over the 14-time Grand Slam winner when asked, in English, at his post-match news conference about the match-fixing allegations.

He said he did not approve of gambling on tennis matches.

"I would take out the betting. But I can't take it out," Verdasco said. "We are trying to fight against that."

For No. 13 Milos Raonic the focus on gambling was an unwanted distraction.

"Tennis is a beautiful [sport]," the Canadian said after winning his first-round match. He called it unfortunate that "the attention of the first Grand Slam of the year is more on that than the Australian Open."