The International Olympic Committee has ordered an investigation into allegations Chinese authorities falsified the age of a double gold medal winning gymnast because she was too young to compete.
Meanwhile, there were thrills and plenty of spills on the BMX track today as the Games' youngest competition ended with golds for France and Latvia, and sweat and tears after a gruelling 50km race walk in relentless sun that ended in gold for Italy.
For once, though, it was controversy rather than sporting excellence that dominated debate on Day 14 of Beijing Games.
China's He Kexin, who won team gold in artistic gymnastics and an individual title on the asymmetric bars, was registered as being born on Jan. 1, 1992.
There have been persistent media allegations that He had competed in earlier tournaments under a later birthdate, and on Thursday an American computer expert said he had uncovered Chinese state documents that proved she was 14 and not 16.
The caption on a photograph published by Chinese state news agency Xinhua last year referred to "13-year-old He Kexin", while China Daily reported in May that she was 14.
An IOC official said the International Gymnastics Federation (FIG) had been asked to look into "discrepancies" over He's age, but others stressed she had already been cleared to compete.
"Everything that has been received so far shows we have no problem of eligibility for these competitors," said the IOC's sports director Christophe Dubi, adding FIG had asked the Chinese national gymnastics federation to investigate.
IOC spokeswoman Giselle Davies added the organisation wanted to clear up the matter 100 percent "and put it to rest".
Gymnasts must turn 16 in the year of the Games to take part, a rule introduced in 1997 to protect their wellbeing, and China's gymnastics coach told a news conference all the team "were in total compliance with the age requirement".
"Since Asian bodies are not the same as Westerners', there have been questions, but there shouldn't be," Chinese head coach Huang Yubin said.
China has invested billions in selecting and training its athletes from a young age, an effort rewarded by top spot in the medals table, with 46 golds. This has been seen as a sign China has the sporting prowess to match its rising superpower status.
There has been criticism of the system even from within China, though, with one former Olympic medallist saying many children who fail to make the grade are left without sufficient education or social skills.
THRILLS AND SPILLS
The BMX competition had been introduced at these Games to attract a younger audience, and produced a thrilling finale.
France's Anne-Caroline Chausson won the women's gold after a tight race with Britain's Shanaze Reade, who crashed on the final bend as she tried to regain the lead.
Maris Strombergs of Latvia won the men's event, avoiding two big crashes that left several riders splayed out on the course.
China may have ruled the medals table, but the Caribbean island of Jamaica has dominated sprinting at these Games, with all four golds in the men's and women's events.
Usain Bolt, who won the men's 100 and 200 metres in world record times, races in the 4x100 relay on Friday aiming for his third gold.
Jamaica are also favourites in the women's sprint relay.
The event, though, has lost a little sparkle after Jamaica's main rivals, the United States, amazingly dropped the baton in the heats of both the men's and women's events.
That topped a dreadful week for the American sprinters in which they failed to win gold for the first time since 1976.
In response to the relay disaster, the chief of the U.S. athletics team ordered a post mortem into a showing which left him "extremely disappointed".
"These are professional athletes who are the best in their field, and anybody who ever ran a high school relay cringes when that baton hits the track," Doug Logan said.
The United States, top of the medals table at the last three Summer Olympics, are badly trailing China, but notched up their 30th gold of the Games on Friday in beach volleyball.
Todd Rogers and Phil Dalhausser won the men's event to complete the double for the U.S. team in the sport.
The Americans hope for more golds in the men's and women's basketball, with the highly-paid NBA players overwhelming favourites to win the gold they embarrassingly missed in Athens.
They play Argentina in the semi-finals on Friday.
Beijing was sunny on Friday after a day of heavy rain on Thursday, bringing a different set of problems for many athletes.
Italy's Alex Schwazer won the 50km walk in Olympic record time despite relentless sun and heat, before dropping to his knees in tears.
Questions about human rights have not gone away. Tibet's exiled spiritual leader, the Dalai Lama, accused Chinese troops of opening fire on protesters in eastern Tibet on Aug. 18.
Beijing Games organiser Wang Wei said Western media were biased and ignorant about the real situation in Tibet. In practice, though, it is almost impossible for foreign journalists to report freely from the troubled region.