Courtsiders have been spotted at the ongoing OUE Singapore Open, allegedly transmitting live updates of the outcomes of points as matches progressed.
The Straits Times understands that at least two men were at the Singapore Indoor Stadium on Tuesday's opening day. The annual competition is a Superseries-level event on the Badminton World Federation (BWF) professional circuit.
The same group were also reportedly at the Malaysia Open, a Superseries Premier tournament held in Kuching last week.
By providing scoring data on-site, often as fast as within milliseconds after a point is played, courtsiders can help to overcome the lag - which can go up to 30 seconds - between live action and televised broadcasts, or when scores are reflected online.
Since this can give punters or bookmakers an edge during in-game betting, courtsiders are often engaged by betting syndicates. For instance, punters can benefit by locking in their bets, before the market closes on betting sites, to make a profit.
International governing body BWF confirmed to ST yesterday the presence of people they believe to be courtsiders.
BWF senior tournament series manager Selvam Supramaniam said that courtsiders infringe on the federation's right to send out its own data to betting companies or partners who have secured such information. He added the BWF is in communication with event organisers Singapore Badminton Association, who are also following up with venue authorities about the issue.
He gave assurance that they will continue to closely monitor the situation over the next few days, but conceded that the authorities' hands are also tied when it comes to taking action such as ejecting people from the arena.
Said Selvam: "What we can do immediately is to have more security, keep going around the area and disrupt their (updating) pattern. The moment there is a delay, people lose faith in that betting company.
"It's difficult to confront them or accuse them simply because (courtsiding) is not illegal in many countries."
Lawyers whom ST checked with said there is nothing that explicitly prohibits spectators from sending out scoring information of a sporting event, but it can become an offence if such activities are linked to betting purposes - something that is hard to prove.
Withers KhattarWong partner Shashi Nathan said: "The difficulty is in proving. There is no offence unless you can prove that they are betting or sending information to an illegal betting site."
Courtsiding is not a new phenomenon at sporting events, particularly at tennis and football competitions. In 2014, a British man employed as a courtsider by a betting company was arrested at the Australian Open, although charges were later dropped.
But Selvam, a veteran BWF official of a decade, said courtsiding only started occurring more in badminton in the last year or so.
It is one of the issues that its integrity unit, formed at the end of 2014, looks into.
He added: "We have stepped up fact-finding from this year. I'm sure in the near future there will be a more robust system in place."