Double Olympic champion Kosuke Kitajima set another national record on Saturday in the Speedo LZR Racer, raising more concerns about contractual obligations for Japan's swimmers to use domestically produced suits at the Beijing Olympics.
Kitajima, who won the men's 100 and 200-meter breaststroke at the 2004 Olympics, clocked a time of 27.65 seconds in the men's 50 meter breaststroke at the Japan Open, breaking his own national record of 27.78 set at the 2005 World Championships in Montreal.
After setting a new national record of 59.53 in the 100 breaststroke on Friday, Kitajima called on Japanese sportswear maker Mizuno to try harder in its quest to come up with an answer to Speedo's suit before Beijing.
While Kitajima is contracted to wear Mizuno at the games the Japan Swimming Federation will meet next week to address the issue, balancing the contract against potential Olympic performance with the LZR Racer.
Since the Speedo LZR Racer was introduced in mid-February, swimmers using the suit have set 37 world records.
Kitajima was among five swimmers to break Japan national records in the Speedo on Friday.
Last month, three Japanese sportswear makers, including Mizuno, introduced new versions of high-tech swimsuits intended to compete with Speedo's suit for Beijing.