Stockholm - Sweden's Ethiopian-born 1500 metres former world champion Abeba Aregawi has tested positive for doping, according to the Swedish Athletics Association (SFIF) on Monday.
The test for banned substances was conducted by the International Association of Athletics Federations (IAAF).
"It is with dismay and with extreme disappointment that we report this issue," said SFIF general secretary Stefan Olsson.
"We totally reject all forms of cheating, doping... We have a zero tolerance, and this is totally unacceptable," said Olsson.
A full investigation will now be conducted, according to the association.
"Because this is an ongoing investigation, we cannot disclose the actual substance that she tested positive for," said Fredrik Trahn, an association spokesman.
"She is provisionally suspended, effective immediately."
The 25-year-old Aregawi, who competed for Ethiopia at the London 2012 Olympics, was world champion in 2013 in Moscow, but finished only sixth in a slow tactical race in Beijing last year.
She has also won the European championships and World Indoors gold over her specialist distance.
She finished fifth at the London Games, again in a slow tactical race, behind Turkey's Asli Cakir Alptekin, who was later stripped of her Olympic title for a second doping offence.
Aregawi switched allegiances to Sweden soon after the Olympics, gaining citizenship through her marriage to a naturalised Swede of Ethiopian origin.