Wimbledon legend Martina Navratilova has called for "weak umpires" to get tough and ensure the All England Club is not defended by grunting.

Portuguese teenager Michelle Larcher de Brito is the latest to raise the decibel level, while the likes of former Wimbledon champions Maria Sharapova, Serena and Venus Williams have all come in for criticism.

Navratilova - who claimed no fewer than nine Wimbledon singles crowns spanning 12 years and 18 Grand Slam titles overall - believes it is a form of "cheating" and should be stamped out by the match officials.

"It needs to be controlled," said Navratilova, who helped launch the HSBC Champions of Wimbledon launch event at the Victoria & Albert Museum in London yesterday.

"The problem is not how loud is it, the question is does it impede the opponent? The answer is 'yes' and something needs to be done.

"It should not be the opponent complaining about it, that is the umpire's job. I should not have to tell him, 'Hey, this is not what the rule book says'.

"The players should not be having that pressure on her because then you say, 'Do I say something after this point? Do I wait for the changeover?
Do I say something? Is it going to get the crowd upset?' Then you are thinking about that instead of playing the game.

"It should not be the player who complains about it, it should be an umpire who says 'You need to cool it down a little bit, this is a warning, do it again and it is a point penalty." Taking a point penalty is going to stop it."

Navratilova declared: "The umpires are weak and they need to be stronger, they need to enforce the rules. The umpires need to take charge."