The suit debate is threatening to blight the entire swimming world championships in Rome next week.

The argument is that the more suits are enhanced, the less athletes rely on their core strength, which reduces the need for a superior physique.

Recently retired three-time Olympian Helen Norfolk says it is unfortunate governing body FINA got scared and has not carried through with its ban, which means anything is allowed.

Norfolk says a case in point is Frenchman Fred Bousquet breaking 21 seconds for the 50 metres freestyle.

"He is a really good swimmer but it just makes people wonder you know, is this really the suit that's doing this - or is it really the swimmer? It's kind of turned into a bit of a laughing stock, because nobody's taking anyone's swim seriously because, you know, if it a really good swim they just blame it on the suit."

Norfolk says you can have a pot-belly and go faster in some cases.

Moss Burmester is first in the pool in Rome, swimming in the 400 metres freestyle on Sunday night. He is looking to be the fifth New Zealander to medal in the event's history. The 200 metres butterfly is his best hope.

Norfolk is his flatmate in Auckland and says Burmester's preparation has been meticulous, starting in Australia, where he swam with Grant Hackett's old coach Denis Cotterill for eight weeks.

"And I know he did some pretty awesome training sets over there. I know that he'll stand up behind those blocks and basically be certain to win a medal."

Alannah Jury has already finished 13th in the 10 kilometre open water event.