Australian swim star Kaylee McKeown has broken a second world record in the space of two days at the World Cup meet in Budapest. 

The 22-year-old Queenslander bettered her own 100m backstroke record on Sunday morning AEDT with a time of 57.33 seconds, shaving 0.12 off the mark that she set in Adelaide before the Tokyo Olympic Games.

It follows her record-breaking swim on Friday evening when she clocked 26.86 for 50m backstroke, eclipsing the previous record of 26.98 set by China's Liu Xiang in 2018.

McKeown was nearly two seconds clear of second-placed Canadian Kylie Masse in the 100m final.

She has earned $US40,000 ($63,350) in bonuses for her two world marks in the Hungarian capital and could add to her record-breaking haul in the 200m backstroke final on Monday morning (AEDT).

McKeown is also in the box seat to claim the overall World Cup series crown, which carries a six-figure bonus.

She is the first woman to hold all three long-course backstroke world records.

AAP