Tennis was the sport involved in 45 per cent of reported cases of suspicious betting during the first quarter of 2017, according to the European Sport Security Association (ESSA).
The international betting integrity body said it has reported 27 cases to relevant authorities in the first quarter of this year.
Tennis was responsible for 12, with football and volleyball the next highest sports with four cases apiece.
Snooker and basketball have two reported cases, with boxing, handball and ice hockey accounting for one each.
"The figures for quarter one follow a similar trend to previous reports," said Mike O'Kane, ESSA chairman.
"We know that tennis, in particular, has been working hard to address this situation and we await with interest the imminent publication of the Independent Review Panel's interim report.
"It is a process that ESSA has engaged in and welcomed as an important step, and we hope that the Panel's recommendations are both evidence-based and provide practical and proportionate actions."
Tennis now has had the highest number of alerts for the last nine months, with nearly 80 per cent of all cases of suspicious betting activity reported in 2016 involving the sport.
O'Kane added that several other important activities around match-fixing are expected this year.
A number of studies on match-fixing, supported by the European Commission, are due to be published this summer.
ESSA have engaged with some of these studies, notably through the establishment of national anti-match-fixing platforms and laws.
"In addressing this issue at any level, there must be a clear understanding that well-regulated betting products, in themselves, neither create nor support match-fixing," O'Kane said.
"That illicit activity is a result of corrupt sportspeople and criminals seeking to defraud betting operators.
"Those operators are the intended victims of that fraud and any mitigating actions will be best served acknowledging that."
Last month, International Tennis Federation (ITF) President David Haggerty announced plans for tours including 750 male and 750 female players.
It is thought that around 14,000 are competing among the full-time ranks, with nearly half of these failing to win any prize money.
This, it is thought, can cause some players to be tempted by corruption.
The ESSA’s integrity report for the first quarter of 2017 can be accessed here.