Nikolay Marfin (pictured top) and Vadim Rakitin were caught  thanks to new testing methods introduced at the London Drug Control Centre in Harlow after each athlete returned adverse analytical findings in blood samples taken from tests conducted just days before the start of the Paralympics.

Both athletes were notified of their failed tests on September 4, the same day the King's College laboratory results were received by the International Paralympic Committee (IPC), and were immediately suspended.

HGH has widely suspected to be among the most abused drugs by some of the world's top athletes.

Testing for it has been in place for every Olympics since Athens in 2004 but this new technique is much more sophisicated.  

It does not detect HGH directly, but rather looks for an unnatural increase in two markers - insulin like growth factor 1 (IGF-1) and another substance, called P3NP, that is produced when bone or collagen is formed - that occurs after injection of HGH.

It is a major breakthrough because it demonstrates that pioneering scientists have developed a test which widens the detection window for the HGH from a few hours to a few weeks, which makes this new version one of the most important breakthroughs in the history of anti-doping.

The new test was only officially approved on the eve of the Olympics, where the only major competitor to be caught for drugs was Belarus' Nadzeya Ostapchuk, who was stripped of the gold medal she had won in the shot put after testing positive for anabolic steroids.

But this case, involving two relatively unknown Russians, will send shockwaves around the world.

"This case is a world-first as some of the latest testing methods were used which were only introduced prior to London 2012," said Toni Pascual, chair of the IPC Anti-Doping Committee.

"These new methods are able to detect misuse of human growth hormone over a span of weeks compared to previous methods used which only detected use over a shorter time period.

The sophisticated Drug Control Centre in Harlow where the two Russian athletes' blood samples were tested

"These findings prove the efficiency and effectiveness of the IPC anti-doping programme in place for the Games."

Rakitin competed in the men's -90kg class at the Games, just prior to the test results being known, and finished seventh.

Marfin was due to compete in the men's +100kg class but, following publication of the results, was prohibited from taking part.

The suspensions will start from August 23, the date when the first blood samples were collected, while all competition results recorded on that date and beyond will be discounted.

A fine of €1,500 (£1,200/$1,920) has also been imposed on each athlete.

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