Japan's Irie fires Rome warning after costume change

Japan's backstroke ace Ryosuke Irie has underlined his world title credentials at the student games in Belgrade despite flip-flopping on his choice of swimsuit.

The 19-year-old, tipped for gold at the Rome world championships later this month, completed a 100 and 200 double in Speedo's drag-reducing LZR suit after a surprise costume switch.

Irie broke the men's 200m backstroke record in May but swimming's governing body FINA refused to ratify the mark as his Descente bodysuit was not on their approved list.

"I was aiming to go under 1:54 so I'm disappointed," Irie told Japanese media after winning the 200m title in the Serbian capital in a time of one minute, 54.13 seconds. He clocked 1:52.86 in Canberra to wipe over a second off American Ryan Lochte's world record set in last year's Beijing Olympic final before FINA ruled Irie's mark would not stand.

American Michael Phelps wore the LZR suit when he won a record eight gold medals in Beijing but Irie had originally said he had no plans to break his ties with Japan's Descente.

Irie has also flirted with the 100m world record, reclaimed by Aaron Peirsol at the US national championships on July 8 in Indianapolis.

But the Japanese swimmer has promised to cut through the red tape and re-establish the 200m world record at the world championships.