Kiwi athletes are warned to be careful of their attire, after a first-of-its-kind doping case

An American athlete tested positive for a performance enhancing drug last year, before proving it got into his system through compression shorts he'd borrowed from a teammate, who later admitted to doping.

The Sport Integrity Commission's Chief Executive Rebecca Rolls says cases of contamination through skin are rare, but it's a growing topic within the anti-doping community.

She says it's a real eye-opener.