Indian Wells tennis chief Raymond Moore has stepped down following his controversial comments about female tennis players. The 69-year-old suggested female tennis players owe their male counterparts for "carrying the sport" and "should get down on their knees" to thank the likes of Roger Federer and Rafael Nadal. Moore later apologised for his "erroneous" remarks. The comments came as equal pay for male and female tennis stars has come into the spotlight. World number one Novak Djokovic also questioned equal pay, saying men should be paid more as their games are more popular. But Serena Williams slammed Moore's statement saying it was "offensive."