France's double Olympic gold medallist Yannick Agnel set a new world record in the short course 400m freestyle event at the French championships on Thursday.

Agnel timed 3min 32.25sec, beating the previous mark of 3:32.77 set by German Paul Biedermann in Berlin in November 2009.

The 20-year-old Agnel claimed a surprise double gold in the men's 200m freestyle and the 4x100m relay with the French team in his first Olympics in London this summer. He also won a silver as part of the 4x200m relay team.

"I was targeting a time close to the world record," Agnel said. "Now, I haven't fixed my limits.

"Up until the end of the week, I've got the 100, 200 and 800m."

Agnel is set to compete in the European short-course championships in the French city of Chartres between November 22-25 after wrapping up his events in the western city of Angers.