Australia’s Mollie O’Callaghan has broken the longest-standing world record in women’s swiming in winning the 200 metres freestyle at the world championships.

O’Callaghan claimed her second gold medal, and first world record, of the meet in Fukuoka by clocking one minute 52.85 seconds in Wednesday night’s final.

The previous benchmark in the event was 1:52.98, set by Italian Federica Pellegrini in the supersuit era in 2009.

Australia’s Ariarne Titmus claimed the silver medal in 1:53.01 after being overtaken by her teammate in the final lap.

“It’s a big honour,” O’Callaghan said. “To come away with the world record is just amazing.”

In the men’s 800m freestyle final, Australia’s Sam Short also won his second medal of the meet in Japan, adding silver in the 800m freestyle title to his earlier 400m freestyle triumph.

Short clocked the quickest time by an Australian – 7:37.76, eclipsing the national record of 7:38.65 set by Grant Hackett in 2005. 

Short led with 50m remaining but was overtaken on the last lap by Tunisia’s Ahmed Hafnaoui, who won in 7:37.00.

The Australian team now has six gold and two silver medals at the titles.