Controversial Russian 5000m runner Olga Yegorova could yet face expulsion from the World Championships after another doping test showed irregularities.

Yegorova tested positive for banned performance-enhancing hormone EPO at the Golden League meeting in Paris last month and was initially banned by athletics' governing body, the IAAF.

But she was reinstated on Saturday on a technicality when it was revealed that French doping authorities had failed to carry out a blood test to back up the results of her urine sample, as IAAF regulations state.

She was tested again in Edmonton - and IAAF vice-president Arne Ljungqvist has revealed that she was one of 11 athletes whose blood tests revealed red blood cell counts outside normal parameters.

Further tests are being carried out on the athletes' urine samples to determine if these readings are the result of the use of banned substances.

"You can get these abnormal concentrations for other reasons," said Ljungqvist.

"These are borderline values with Yegorova. It's not necessarily a reason for going ahead, but we must make sure because of the tests in Paris."

The samples have been sent to Lausanne and a result is expected before the first heats of the 5000m on Thursday.

Newly-crowned 1500m champion Gabriela Szabo, who had previously threatened to boycott the 5000m if Yegorova were allowed to compete, said on Wednesday that she would now definitely be running.

Of all the athletes tested at the championships so far, only Yegorova was specifically targeted by the authorities.