Berlin - Usain Bolt has established himself as a global sports icon while the case of Caster Semenya could have been treated with more sensitivity, world athletics supremo Lamine Diack said on Sunday.

Speaking on the closing day of the Berlin championships, the IAAF president Diack said that the sport had been as successful as at the 2008 Beijing Olympics where Jamaica's Bolt had burst onto the scene.

"We have been living a fantastic championship. All the promises from Beijing have been kept," the 76-year-old Senegalese said.

"Usain Bolt is the most popular sportsman, not just the most popular athlete."

Bolt repeated his Olympic sprint treble in Berlin and set jaw-dropping world records in the 100m (9.58 seconds) and 200m (19.19). The 23-year-old now enjoys pop star status.

On the downside there was the case of 800m champion Semenya who was told by the IAAF to undergo a gender verification test over concerns about her meteoric rise and boyish looks.

"The issue could have been treated with more sensitivity. I admit that we are unhappy, we could have done better," said Diack. "But this is definitely not a case of racism."

The whole of South Africa rallied behind the athlete, who won the gold a few hours after the IAAF confirmed that the tests had started, with results due within the next weeks.

South African athletics boss Leonard Chuene allegedly threatened to resign from the IAAF Council during a stormy meeting on Saturday.

Diack praised the overall running of the championships which brought together 1,984 athletes from 201 countries and attracted some 400,000 fans to the Olympic Stadium as the biggest sports event of the year.

Diack praised the spread as 34 countries medalled ahead of the concluding eight finals Sunday and 55 countries had athletes in finals.

IAAF spokesman Nick Davies said that 900 of the planned 1,000 doping tests have been conducted. There have been two positive tests so far, involving Nigerian 400 metres hurdles runner Amaka Ogoegbunam and Moroccan steeplechaser Jamal Chatbi. (dpa)