The Japan Swimming Federation said Sunday that starting next month it will only officially recognize Japanese records which have been achieved in swimwear approved by swimming's world governing body FINA.
The announcement came after FINA publicized a list on Tuesday of swimwear which it approves based on a new set of guidelines.
Part of the requirement states that "swimsuit material shall not be constructed to or include elements/systems which create air/water trapping effects during use."
The JASF also said it will require swimmers competing in official meets to don swimsuits recognized by FINA starting from April 1, 2010.
Racers in swimwear that has not been recognized by FINA will be permitted up until March 31, 2010, considering the fact that it will take time for all Japanese swimmers to obtain such outfits.
FINA did not approve the swimsuit worn by Ryosuke Irie, who broke the men's 200-meter backstroke world record in a time of 1 minute, 52.86 seconds at the inaugural Canberra swimming meet between Japan and Australia on May 10.
Many of the swimsuits worn at the national championships by swimmers who set Japanese records last month also failed to gain FINA's seal of approval.
The JASF has said it intends to recognize Irie's mark as a national record, even if FINA does not approve it as a world record. The JASF will also recognize any national records which were set in April and May.