American teenager Katie Ledecky smashed the world record in the women's 1,500 metres freestyle final by more than six seconds during a glittering session for the United States at the world championships in Barcelona, Spain on Tuesday (July 30).

The 16-year-old from Bethesda, who also won the 400 freestyle gold medal on Sunday (July 28), powered away from defending champion Lotte Friis of Denmark in the final stages to break the previous best of 15:42.54 set by compatriot Kate Ziegler in 2007.

It was the second world record of the championships in the specially constructed pool after Ruta Meilutyte's mark in qualifying for the 100 metres breaststroke on Monday (July 29).

Lithuanian Meilutyte, born two days after Ledecky in March 1997, went on to claim a first world championship gold for the tiny Baltic nation when she triumphed in Tuesday's final.

Presented by Adam Justice