Dunn had set an S14 world record of 1min 53.57sec in Berlin earlier this year during the World Para Swimming World Series.

He clocked 1:52.96 for gold at the Aquatics Centre in London as he led home a British podium sweep.

Thomas Hamer was second in 1:55.19, while Jordan Catchpole touched home in 1:56.23 to take bronze.

There was more golden delight for Britain as S8 swimmer Alice Tai won the women's 100m freestyle title.

Tai was crowned as the World Para Swimming World Series champion in June, setting seven world records in the series finale in Berlin.

A year out from the Paralympics, to be held in Tokyo between August 25 to September 6, 2020, Tai underlined her dominance, winning the world title in 1:03.77. 

American Jessica Long was second in 1:06.08 as Claire Supiot of France earned bronze, just 0.03 behind.

Further world records were set by Chinese Yuyan Jiang and Simone Barlaam of Italy.

S6 swimmer Jiang claimed gold in the women's 400m freestyle final in 5:13.32 as she eclipsed the 5:14.69 mark set by Ukrainian Yelyzaveta Mereshko in May 2016.

Mereshko had to settle for silver in 5:17.49, with British star Ellie Simmonds earning bronze in 5:21.78.

Barlaam lowered the men's 100m freestyle S9 world record by 0.08 to clinch gold in London.

The Italian clocked 54.10 to duck under Australian Rowan Crothers' world best time of 54.18.

Russians Denis Tarasov, in 56.34, and Bogdan Mozgovoi, in 56.71, collected silver and bronze, respectively.