Tennis authorities may have bungled the first corruption investigation since a match-fixing scandal tarnished this year's Australian Open, with a player involved in a suspicious match at the tournament allowed to leave Melbourne without being interviewed, or having his phone seized.
It has also emerged that a major European-based punter previously linked to lucrative wins on other suspicious matches bet on the Australian Open mixed doubles match between David Marrero and Lara Arruabarrena and Lukasz Kubot and Andrea Hlavackova on   January 24, in a development that concerned authorities. 
Pinnacle Sports, an international bookmaker, suspended betting an hour before the match because of the amount wagered on Kubot and Hlavackova - who won in straight sets after only 49 minutes -  but of greater interest to authorities is who was making the bets.
Pinnacle handed betting data to Victoria Police's sporting integrity intelligence unit, which is investigating the match.
Suspicions surrounding the match centred on Marrero, who has previously been linked to other dubious results.
But it is believed the TIU, the anti-corruption body established by tennis authorities, allowed Marrero to leave Melbourne - after he met the coach of another player at the coach's hotel - for his native Spain, and then sent him an email several days later requesting a meeting. Arruabarrena is also Spanish.
In the email, it is understood Marrero was told not to delete any information from his phone as it could be seized, in an exchange described as almost comical by a senior law-enforcement figure.
The delay in interviewing Marrero, and examining his phone records, could mean it is impossible to gather evidence that may substantiate suspicions about betting on the match, the figure said.
They compared the TIU approach with horse racing, where jockeys are called immediately into an integrity hearing to explain a suspicious ride.
The TIU has repeatedly stated that suspicious betting data is not enough evidence to prove a corruption offence.
It is unclear whether Marrero has yet been interviewed, almost a month after the suspicious match, as he has since played tournaments in Argentina and Brazil, where he was a doubles finalist and pocketed $21,000 with his partner.
After his Australian Open loss, Marrero denied fixing the match. He had not played as well as possible because of a knee injury, he said, and because he sometimes held back when playing mixed doubles.
Marrero only won his serve once and made numerous unforced errors.
"Normally, when I play, I play full power, in doubles or singles," he said.
"But when I see the lady in front of me, I feel my hand wants to play, but my head says, 'Be careful.' This is not a good combination."
The investigation will probe whether Marrero deliberately threw the match, or informed someone he was playing hurt. He has a poor mixed doubles record but has been ranked as high as five in world doubles.
Even if Marrero could not have foreseen that the information relating to his injury may be used to bet on the match, it could still constitute a sports corruption offence under Victorian law, if it was found that sharing that information was "reckless" conduct.
It would also constitute a corruption offence as part of the Tennis Anti Corruption Program, which is enforced by the TIU, and could be punished with fines of $250,000 and lifetime bans.
A TIU spokesman would not comment on whether Marrero or any of the other players had been interviewed, or whether the process undertaken by investigators was common in corruption probes.
"TIU does not make public comment on its investigative activities and as this is an ongoing case we are not able to respond to your questions at this time."
Victoria Police received international acclaim for their match-fixing investigation surrounding the Southern Stars, and were responsible for the first Australian criminal case involving tennis match fixing, which had few international precedents.
Pinnacle was accused of a publicity stunt after its head of sports, Marco Blume, told the New York Times he had suspended betting.
Mr Blume declined to comment further on why the markets were suspended, whether the involvement of the European punter was significant, or when tennis authorities were informed of the decision.
Kubot and Hlavackova claimed after the match that they had been interviewed by the TIU, and reported to investigators that they had not noticed anything untoward.
But Arruabarrena, in a spirited online post defending her integrity, makes no mention of being interviewed, and conversely seems to suggest she did not know there were fixing suspicions until hours after she left Melbourne, when she checked her phone during a flight stopover in Dubai. 
She published the defence four days after the match, when she had returned to Spain.
Marrero and Arruabarrena, and their coaches, could not be reached.
Tennis' governing bodies announced last month that its anti-corruption measures would be subject to an independent review.
The review by British QC Adam Lewis will probe whether the TIU is properly resourced, a constant criticism that may have hampered the Marrero investigation.
Mr Lewis will also review whether the unit has sufficient powers, but unit investigators can already demand that a player suspected of a corruption offence provides telephone and banking records within seven days.