Caroline Wozniacki has claimed that female tennis players scream loudly during tennis matches "on purpose".
The 21-year-old believes that a number of female competitors grunt in order to gain a tactical advantage.
"I think there are some players who do it on purpose," ESPN quotes Wozniacki as saying. "They don't do it in practice and then they come into the match and they grunt.
"I understand if they do it in practice and in matches, that's different. But I think [officials] could definitely cut it.
"If you grunt really loudly, your opponent cannot hear how you hit the ball."
The world number one will face Vera Zvonareva in the Red Group of the WTA Championships after defeating Agnieszka Radwanska 5-7 6-2 6-4 in the opening match.
