Irish athletes at this year's Winter Olympics in Sochi competed alongside Russian athletes who have admitted taking drugs that have now been placed on the World Anti Doping Agency (Wada) banned list even though there is no test available to detect them.

The Russian athletes, who won 33 medals, 13 of them gold, have admitted to taking Xenon – a drug that has the same effect as the outlawed Erythropoietin (EPO), which boosts oxygen-carrying red blood cells.

Among other things Xenon is used to anaesthetise hospital patients and as a satellite propellant. From September 1st it has been banned for use by athletes.

A relative of Xenon, called Argon, has also been placed on the banned list as it possesses similar qualities. But Wada has yet to develop a test that can tell if athletes are using the substances.

"The point is, the whole area of intelligence is very important in doping and anti doping," said Dr Una May, director of the Irish Sports Council's anti-doping unit. "Just because there is no test for Xenon now does not mean that it is okay to take it. You make it clear that you should not use it."

Increased use of Biological passports may also be a deterrent to using the drugs that first came to light after Russian skiers and biathletes admitted to using Xenon at the Sochi Olympics in February.

The team’s coach told German reporters that they used the gas because it wasn’t illegal and that it mimicked the effects of training at altitude. Their admission forced Wada to ban the drug.

Seán Greenwood, Séamus O’Connor, Conor Lyne, Florence Bell and Jan Rossiter comprised the Irish team that competed at Sochi.

An ethical debate has now ensued as oxygen tents, which also increase red blood cell counts artificially, are not illegal, while Xenon and Argon, which

produce the same effects, are.

Although Argon makes up less than 1 per cent of the Earth’s atmosphere and Xenon exists in tiny quantities, the Russian athletes are believed to have been breathing a mixture of 50 per cent oxygen and 50 per cent Xenon.

In many countries the technology and expense to provide such quantities of the gasses as well as the delivery system (inhaling) are beyond reach, but scientists believe that their use is potentially lethal. Given the anaesthetic properties, excess intake could be lethal.

Doping with artificial EPO has been one of the biggest threats to the integrity of sport over the past 20

The initial clampdown on using EPO

meant scientists attempted to develop other formulations to circumvent tests and banned lists.

Xenon and Argon are the latest to emerge, with Krypton likely to be added.

“As soon as something is on the banned list, it is targeted by Wada,” said Dr May. “It’s is just like the early days of EPO where the athletes moved away from the original and used different brands of the same substance. Wada developed tests to deal with that.”

Successful research has been conducted to detect the substances. But so far there is nothing in place that would stand up to legal challenge in the Court of Arbitration for Sport.

The drugs are not well known, although Xenon has been extensively used in Russia as an aesthetic with no side effects for decades. Irish athletes have been alerted.

“Once it’s on the Wada list it should go out to Irish athletes. That’s the way it normally works,” said Dr May. “Xenon is not well known . . . But Wada saw the potential there and decided to act quickly.”

It is not sure whether or not an effective test can be developed before the end of this year.