The ATP is aiming to hit the delete key on 15 gamblers charged with placing internet bets at tournaments to exploit a 20-second delay in scores transmitted to bookmakers.

The ATP has sent the names and credit card numbers of the 15 gamblers to organizers of next week's Madrid Masters Series event and asked the tournament to deny entry to the gamblers, Madrid tournament official Gerard Tsobanian told Bloomberg in an interview today.

"It's a very international list," Tsobanian told Bloomberg. "Some of the gamblers have tried to get into past tournaments by posing as journalists."

ATP spokesman Kris Dent declined to comment "on the specifics of many measures we have in place to deal with integrity measures," according to the Bloomberg report.

Last February, three internet gamblers were bounced from the stands of the Sony Ericsson WTA Tour's Proximus Diamond Games in Antwerp after the trio were caught logged on to a betting web site making bets while matches were ongoing in Antwerp.

"Three spectators were removed. The two Russians and one German were holding a laptop and logged on to a gambling website and were gambling on ongoing matches," tournament spokeswoman Katia Stroobants said. "[They were] exploiting the delay between the time a point was won and the time it appeared on the official tournament website."

A Sony Ericsson WTA Tour spokeswoman said security asked the trio to leave the building or give up their laptops.

"The WTA takes a zero tolerance approach to this issue," the spokeswoman said. "The men were asked to leave or hand over their laptops and they decided to leave with their computers. Unfortunately we do not have any other powers."

The incident came less than four months after French undercover police were invited by BNP Paribas to join former players in roaming the stands looking for any signs of online gambling during the Paris Indoors ATP Masters Series event last fall.

Theoretically, gamblers at a tournament site could exploit the 20-second time delay, particularly in the case of a tiebreaker or injury to one player.

Mark Davies, a spokesman for British bookmaker Betfair, told Bloomberg he's heard rumors of such activity though "I haven't seen it in practice."