Michael Phelps has broken the world record in the 100metres butterfly at the US Championships in Indianapolis.

Phelps recorded a time of 50.22 seconds to break the previous mark of 50.40sec set by Ian Crocker at the 2005 World Championships in Montreal.

The world record comes less than three weeks after Phelps missed it by 0.08 seconds with a time of 50.48sec at the Canada Cup in Montreal.

The 14-time Olympic gold medalist dominated this final, finishing 0.84 seconds ahead of Tyler McGill to earn a place in the event at the world championships in Rome next month.

He has also qualified in both the 200m fly and 200m freestyle events.

Phelps returned to competitive action in May after being banned for three months in February by USA Swimming. The governing body also withdrew all financial support after a photograph was published of him apparently inhaling from the type of glass pipe often used to smoke cannabis.