Spanish middle-distance runner Marta Dominguez has been banned for three years by the Court of Arbitration for Sport (CAS) due to a breach of anti-doping regulations.
The 40-year-old is also set to be stripped of the steeplechase world gold medal she won in Berlin in 2009 as a result of anomalies in her biological passport.
Dominguez was provisionally suspended by the IAAF in 2013 and banned for four years, but was cleared of any wrongdoing by the Spanish Athletics Federation (RFEA) in a hearing last year.
The IAAF and the World AntiDoping Agency (WADA) launched an appeal against that RFEA ruling with CAS and the verdict was announced on Thursday.
A CAS statement said: "The Panel found that none of the explanations offered by the RFEA or Marta Dominguez were sufficient for the Panel not to be comfortably satisfied by the scientific evidence presented by WADA and the IAAF's experts that an anti-doping rule violation had occurred.
"Accordingly, the Panel set aside the RFEA Decision and found Ms Dominguez guilty of an anti-doping rule violation. With respect to the sanction, the Panel found that a three-year period of ineligibility was appropriate.
"The suspension commenced on 24 June 2015, with the period of provisional suspension (8 July 2013 until 19 March 2014) credited against the period of ineligibility to be served.
"The Panel also ordered that all competitive results obtained by Ms Dominguez from 5 August 2009 (date of the first of several sample collections) until 8 July 2013 (commencement of provisional suspension) be disqualified."
Dominguez was crowned world steeplechase champion over 3,000 metres six years ago and also won silver at the European Championships a year later.