USA's Katie Ledecky breaks her own world record in 1500m freestyle

The USA's Katie Ledecky has put her name in the record books yet again by smashing her own world record in the 1500m freestyle at the World Championships in Kazan this morning.

The 18-year-old, who won gold in the 400m freestyle final on Sunday, clocked a historic time of 15:27.71.

The American pulled away from the field early on in heat three before picking up the stroke rate to move inside the world-record time at the midway point.

Ledecky, who set the previous record of 15:28.36 last year, dropped the pace slightly in the final 100m stretch, but came through comfortably.

Meanwhile, Great Britain's Jessica Thielmann failed to make tomorrow's final after finishing fifth in heat two in a time of 16:21.21, making her 10th fastest overall.