JUKKA Harkonen has managed some of the all-time greats like Frankie Fredericks and Marie-Jose Perec and is an adviser to a lot of African athletes.
In November he was in Pretoria, South Africa, watching some juniors train when he spotted one which stood out of the pack. "Who's the boy?", he asked.
The boy was Caster Semenya.
He was blown away so kept his eye on Semenya although he warned the South African authorities that they should do all the relevant gender tests because he knew questions would be asked.
And they have been ever since Semenya produced an extraordinary performance in the 800m at the African Junior Championships this year of 1min56.72sec.
Harkonen has told associates he has been convinced that all the tests, including a visual examination, have been done and that the 18-year-old is clear to compete as a woman.
The South African authorities have dismissed claims the IAAF is considering withdrawing Semenya from the 800m final which was being run overnight.
However, the sport's leading body has been active on the issue during the world championships collating the results of testing and getting scientific advice.
One official said: "There has been an investigation into her eligibility and that can be on three levels, eligibility regarding doping, eligibility regarding nationality and eligibility regarding gender.
"Sources who have had the opportunity of being very close to her would seem to think she is more of a man than a woman.
"She has got the arms, the forearms, the throat and the facial hair of a young boy. They will keep coming up and saying she has passed the test but the test isn't perfect anymore."
Comparisons have been made with Olympic 800m champion Marie Mutola whose gender was questioned throughout her career.
Australian coach Nic Bideau, who has been around the international circuit for 20 years, said often the African nations produce these people who are born with a mixture of chromosomes and display both male and female characteristics.
"There are three divisions," he said. "There are men, there are women and there are Mutola's. They are not proper women but they're not really men.
"The only real test is visual and if you pass it then you have passed. They knew before Semenya ran here that it was going to be a big issue and so my understanding is they have done all the tests."
The most famous case of ambigious gender was Poland's Olympic gold medal sprinter Stella Walsh who won the silver medal in the 100m at the 1936 Olympics in Berlin.
Walsh died in 1980 when she was shot as an innocent bystander during an armed robbery in the USA. An autopsy found that Walsh had male genitals and both male and female chromosomes -- a condition known as mosaicism.