LONDON (Reuters) - The organization tackling the threat of match-fixing in tennis has received 48 alerts this year, mostly from the lower tiers of the professional ranks.
A briefing note from the Tennis Integrity Unit (TIU) on Friday said 24 men's matches on the Futures Tour and 10 women's matches from the entry-level ITF circuit had aroused suspicion.
One grand slam match triggered an alert and one from the WTA Tour but there were none from the men's ATP Tour. The men's Challenger circuit, one rung below the main Tour, had seen 12.
Alerts are forwarded to the TIU from the betting industry when there is "unusual or suspicious activity" around a match.
A full investigation can follow should the TIU believe corrupt activity was likely, although it said alerts were not necessarily indications of wrongdoing.
"Every alert received by the TIU is assessed and followed up as an indicator that something inappropriate may have happened," the TIU said.
"It is important to appreciate that an alert on its own is not evidence of match-fixing. There are many reasons other than corrupt activity that can explain unusual patterns."
The reasons, it states, can be incorrect odds setting, player fatigue or injury and playing conditions.
There have been 24,110 professional matches played around the world this year, meaning only 0.2 percent of them had been flagged up by the betting companies.
Match-fixing allegations by the BBC and online BuzzFeed News broke before this year's Australian Open with the TIU criticized for not adequately investigating some 16 players repeatedly flagged over suspicions they had thrown matches.
Tennis governing bodies since set up an independent review panel to investigate allegations of corruption in the sport and the effectiveness of existing procedures.
That is expected to take around a year.
In response to the suggestions the TIU's handful of full-time staff was insufficient to deal with vast amounts of match data, the organization has begun to beef up its operation.
On Friday it confirmed it will hire another data analyst and another investigator to join TIU director Nigel Willerton's team.
Editing by Ed Osmond