Former 1,500-meter world champion Abeba Aregawi has failed a doping test and has withdrawn from competition pending an investigation.

World track and field body the IAAF says a urine test indicated the presence of a banned substance.

The IAAF did not identify the substance but says it showed up in an out-of-competition test which the governing body conducted on the 2013 world champion.

The IAAF says Abeba, who was born in Ethiopia but now represents Sweden, voluntarily withdrew from competing and has asked for her backup "B'' sample to be tested.

The 25-year-old Abeba is the current world indoor champion in the 1,500 meters. She also won the European indoor title in 2013.