Sydney - South African Penny Heyns broke her own world record in the women's 200 metres breaststroke at the Pan Pacific swimming championship in Sydney on Thursday.
The 24-year-old Olympic champion swam 2min 24.42sec in a semi-final to better her record of 2:24.51 set last month in Los Angeles.
It is Heyns' sixth world record in six weeks. Heyns also lowered her world record in the 100m breaststroke heats on Monday, clocking 1:06.52.
Heyns had previously broken the 100m breaststroke world record twice in one day in Los Angeles on July 18. She brought the time down to 1:06.95.
There have now been eight world records set at the meet in the first five days.
The women's 200m breaststroke final is on Friday. - Sapa-AP