Imagine someone who has the speed of Usain Bolt, the leap of NBA star LeBron James and the stamina of swimmer Sun Yang - he or she would be an athlete virtually unbeatable.

Yet the possibility is not so far-fetched, as scientists warn the development of gene technology poses a serious challenge to anti-doping efforts.

Gene doping is the non-therapeutic use of DNA to enhance performance, and according to experts, has the potential to create super athletes.

"With the growing potential of genetic cures for muscle diseases and blood disorders comes the growing threat of misuse by the sports world," Arne Ljungqvist, vice-president of the World Anti-Doping Agency, said last week at the close of the Fourth Gene and Cell Doping Symposium in Beijing.

Introducing genes to the human body can increase an athlete's muscle power, stamina and pain resistance, giving them a competitive edge.

WADA has not found any evidence suggesting the use of gene doping in sports so far, but it has still allocated $15 million to research on risk and detection methods since the first symposium in 2002.

"We should be proactive," said Ljungqvist, who is also chairman of the International Olympic Committee's Medical Commission.

"We do have evidence that there is an interest out there in certain circles," he added. "There seems to be mental readiness to take it once it is made available in a safe way."

Other participants at the two-day meeting, which included more than 70 gene experts, anti-doping scientists and sports ethicists, echoed Ljungqvist's concern.

Li Ning, president of the Beijing You'an Hospital and a renowned gene therapist, urged the world to keep an eye on the potential threat.

"Any cutting-edge technology is a double-edged sword," he said. "I feel it won't take long before someone eventually misuses the technology for illegal purposes because the genetic edge is so overwhelming."

For example, Finnish cross-country skier Eero Mantyranta was found to have an innate mutation, which made his body produce abnormally high amounts of red blood cells and increased oxygen capacity up to 50 percent.

With greater stamina, Mantyranta claimed seven medals, including three gold, at the 1960, 1964 and 1968 Winter Olympics.

Although it has not been proved, the technology is advanced enough to produce another Mantyranta artificially. A reliable detection method is also yet to be found.

"It's much more complex (than detecting conventional doping)," said Patrick Diel, a professor of endocrinology and biochemistry at German Sport University Cologne.

As nothing unusual would enter the bloodstream in gene doping, traditional blood and urine sample tests would not work.

Diel said it will be easier to identify the abnormal by analyzing sharp physiological changes before and after potential doping applications.

"It doesn't matter what technique you use," he said. "If some parts are changing in your body and your bio pattern is changing, then the technology can detect it."

Theodore Friedmann, chairman of WADA's gene-doping panel, agreed, but said signs of gene doping are subtle and can be easily confused with physiological changes resulting from a diet or illness.

Still, WADA said it believes a reliable testing method is not far away.

"I hope we are not very far from it," said Ljungqvist. "We always have a hope that for the next Olympic Games (in Rio in 2016) we will have a proper method in place."

While it offers the potential for enhancing sports performance, experts said gene doping also carries potential risks such as serious genetic damage, including cancer.

However, Zhao Jian, deputy director of the China Anti-Doping Agency, is more concerned about the potential ethical issues that come with health harms.

"Will it transfer to the next generation and who will we compete against in the future - human or artificial creature?" he said. "We still have much to learn about how things can go wrong."