A Japanese runner who tested positive for a banned stimulant after an April 22 race in Kobe has received a warning from the Japan Amateur Athletic Federation, officials said Monday.

The JAAF also annulled the record of Minori Hayakari, who finished second in the women's 1,500 meters at the Hyogo Relay Carnival, after she tested positive for phenyl-propanolamine.

Hayakari, 28, said she took cold medicine without knowing it contained a banned substance.