Swimmer Matthew Cowdrey became Australia's most decorated Paralympian on Wednesday, smashing his own world record as he claimed an historic 11th gold medal.

The 24-year-old, an amputee since childhood, finished the S9 50m freestyle in a new world best of 25.13sec – leaving Tamas Toth of Hungary to pick up the silver and Spain's Jose Antonio Mari Alcaraz to take the bronze.

Cowdrey has already won two golds in the S9 100m backstroke and the 4x100m freestyle relay 34 points, as well as two silvers in the S9 100m butterfly and SB8 100m breaststroke.

He is still to race in the S9 100m freestyle and SM9 200m individual medley.

He won five gold and three silver medals four years ago in Beijing and broke five world records. In Athens in 2004, he won three golds.