Thanou was suspended for two years in 2004
Controversial Greek sprinter Katerina Thanou has been awarded Marion Jones's 100m silver medal from the 2001 World Championships in Edmonton.
The IAAF annulled all the medals Jones had won since September 2000 after she admitted using the banned steroid THG.
Athletics' governing body was reluctant to award the silver to Thanou, who was suspended after missing three drugs tests on the eve of the 2004 Olympics.
Yet IAAF spokesman Nick Davies said: "Legally, we had no other choice."
He added: "There was no evidence of Thanou committing any doping offence during the period in question, which leaves us with no alternative but to award the medal to her."
The International Olympic Committee is set to decide how to reallocate Jones's five medals from the 2000 Sydney Olympics at a meeting of its executive board in Beijing next week.
Thanou finished second behind the American in the 100m in Sydney and her lawyer, Gregory Ioannidis, has said she could be willing to take legal action if the gold is not now given to her.
The IOC has previously indicated it would follow the lead of the IAAF in making its decision.
Jones was imprisoned after lying to US investigators
Ioannidis welcomed the decision of the IAAF, telling BBC Sport: "This is indeed good news.
"It is a fair and just decision which equally respects the rights of the individual athlete and of the sport."
Last year IAAF vice-president Seb Coe told the BBC he would be "uncomfortable" with Thanou being awarded any of Jones's medals.
However Ioannidis told BBC Sport last December that his client could sue the IOC if she was not awarded the Sydney gold.
The Greek sprinter and her compatriot Kostas Kenteris missed drugs tests on the eve of the Athens Olympics.
It was the third time they had missed tests, resulting in a two-year suspension that expired at the end of last year.
The pair still face criminal charges of perjury and falsifying evidence in Greece after claiming they had been injured in a motorcycle crash on the eve of the Games.
Last October, Jones disclosed that she had taken THG from September 2000 to July 2001.
She also admitted lying to US investigators about her drug use, resulting in a six-month prison term.
Ukraine's Zhanna Block claimed the gold medal at the 2001 Worlds in Edmonton.