WADA director general David Howman said he had held "fruitful and positive'' talks in London today with national and international athletes' groups from various professional sports, including football, athletics, cricket and rugby, to allay their concerns over the revised rules, especially the one that requires athletes to provide their daily whereabouts for out-of-competition doping controls.

 

Howman said: "One of the major complaints they have had is not being involved in consultation.

 

"We feel we should be hearing from them and we will make sure that happens in the future.''

 

Under the latest WADA code that went into effect on January 1, athletes must give three months' advance notice of where and when they can be located for testing one hour a day - seven days a week, between 6am and 11pm.

 

The information is registered online and can be updated by e-mail or text message.

 

Previously, the rules applied only five days a week and athletes would only have to be at the stated location for a portion of that hour.

 

Nadal and Britain's Andy Murray have been among the outspoken critics of the new system. Williams called the rules "over the top'' and "very invasive.''

 

Nadal said players feel they are being treated like "criminals.''

 

In Belgium , 65 athletes have filed a court challenge against the WADA rules.

 

Howman said: "We feel reasonably confident that whatever challenge we receive going forward will be met.

 

"If there are justifiable technical complaints, we'll listen."

 

Under the rule, three missed tests or three warnings for failing to file whereabouts information within an 18-month period constitute a doping violation and can lead to sanctions.

 

It is the same rule that led to Britain's Olympic and world 400 metres champion Christine Ohuruogu being banned for a year in 2006 after she was not where she was supposed to be on three occasions.

 

Howman said he had received reports of only three filing failures so far.

 

Among the groups meeting with Howman was the Professional Footballers Association (PFA), which represents football players in England .

 

Brendon Batson, the PFA's deputy chief executive, said: "We've got concerns about the whereabouts rules and filing violations.

 

"If athletes don't input the correct info, and testers turn up, they could have a strike against them.

 

"At least we were able to put these real concerns to WADA .

 

"In the past we haven't had that opportunity.''