Szabo has withdrawn a threat to pull out of the 5,000m

IAAF general secretary Istvan Gyulai said: "He did compete, but won't again. You wouldn't know the name."

"We can't yet release the name. We have to talk to the country's federation."

A spokesman added: "According to IAAF regulations, the athlete's member federation will be informed of the results of the test.

"The IAAF will only announce the outcome of the test if the B sample analysis confirms the A sample result."

Gyulai said the urine tests of six other athletes, including Yegorova's, showed no evidence of EPO use.

Their urine was tested after blood tests showed elevated red blood cell counts, a possible indicator of EPO use.

Boycott threat

EPO is a drug which can dramatically improve performances in middle- and long-distance running.

Yegorova's ban was lifted last Sunday but IAAF vice-president Arne Ljungqvist has said she was targeted for a fresh EPO test in Edmonton.

Romanian Gabriela Szabo last week threatened to withdraw from the 5,000m, and thus fail to defend her 1997 and 1999 world titles, if Yegorova was allowed to run.

But Szabo, who already has won the 1,500m world title in Edmonton, said on Wednesday that she will run against Yegorova.

The two athletes were drawn in the same first-round heat and are due to run against each other on Thursday.

The test for EPO, which was at the centre of the 1998 Tour de France doping scandal, was introduced into athletics for the first time at last year's Sydney Olympics.