Rashid Ramzi(1)July 27 - Bahrain's Rashid Ramzi (pictured), the Olympic 1500 metres champion, faced disciplinary hearing today to explain why he tested positive for the blood-boosting drug CERA after the Beijing Games.

The Morocco-born athlete was one of five athletes who had their cases heard by the International Olympic Committee (IOC) panel.

CERA (ContinuousErythropoiesis Receptor Activator) is the latest generation of Erythropoietin (EPO).

They were caught this year in new tests using blood samples taken at the Games, but all deny doping.

The others are Italian cyclist Davide Rebellin, who won silver in the road race, German cyclist Stefan Schumacher, Croatian 800m runner Vanja Perisic and Greek race walker Athanasia Tsoumeleka.

A sixth athlete, women's weightlifter Yudelquis Contreras, was initially found positive in the retesting process.

But the Dominican Olympic Committee cleared her last month after the B-sample came back negative.

The IOC can strip athletes of their results and medals, and ban them from the 2012 London Olympics.

Disciplinary panel member Denis Oswald said rulings were expected when the IOC's ruling Executive Board meets in Berlin on August 13 and 14.

Oswald said: "Some of the cases have to go to the Executive Board and the intention is to announce all the results together.

"There's quite a lot of arguments and we now have to study them."

Ramzi emerged from the IOC headquarters with his Los Angeles-based lawyer Maurice Suh - whose previous clients in doping cases include former Olympic 100m champion Justin Gatlin and cyclist Floyd Landis - around 90 minutes after the hearing started.

Neither commented on the case, though Suh later issued a statement outlining the runner's defence.

He said the new test for CERA was not certified when Ramzi's sample was tested; that the test produced a negative B result for another athlete; and documents to explain how the sample went from Beijing to the laboratory in Paris were missing.

Suh said: "The utmost care should be taken to ensure that the process is fair to Mr Ramzi."

Davide 2520RebellinRebellin's (pictured) lawyer Fabio Pavone said on arriving that the Italian was "completely innocent'' of doping.

Pavone said: "He has always been a clean athlete and he intends to demonstrate that.

"He is confident because he has nothing to hide."

Schumacher said he was "hopeful'' after a 90-minute hearing.

He said: "I have to fight for my rights because I know I didn't do anything wrong."

Schumacher's lawyer Michael Lehner said he argued that testing processes in the Paris laboratory did not follow World Anti-Doping Agency standards.

"They took the same people [to work on] the A and B samples so the results are not valid.

"They can't ban Stefan Schumacher."

Perisic and Tsoumeleka did not appear in person and were represented by lawyers.

The disciplinary panel was chaired by IOC vice-president Thomas Bach of Germany, and included Switzerland's Oswald, Gerhard Heiberg of Norway and Frank Fredericks, Namibia's four-time Olympic silver medallist.

The IOC can disqualify athletes from the Games though suspensions must be imposed by an Olympic sport's international governing body.

Under new IOC rules, any athlete caught doping and banned for at least six months cannot compete in the next Olympics.

The athletes tested positive for CERA, an advanced version of the endurance-boosting hormone EPO, when a new lab test was made available following the Olympics.

The drug was also found in tests of backup B-samples, allowing the IOC to open disciplinary cases.

Ramzi was the first gold medalist from Beijing caught for use of performance-enhancing drugs.

He gave Bahrain its first ever Olympic track and field gold medal with victory in the 1500m in 3min 32.94sec.

If Ramzi is stripped of the victory, Asbel Kipruto Kiprop of Kenya stands to be upgraded from silver to gold.

Nick Willis of New Zealand would go from bronze to silver, and fourth-place finisher Mehdi Baala of France would get the bronze.

Rebellin finished second behind Spain's Samuel Sanchez.

If he loses his medal, Switzerland's Fabian Cancellera would move to silver and Russia's Alexander Kolobnev to bronze.

Tsoumeleka, who won the Olympic 20 kilometres walk gold in 2004, Perisic and Schumacher did not win medals in Beijing.

The IOC previously disqualified nine athletes for doping at the Beijing Games.

They included Ukrainian heptathlete Lyudmila Blonska who was stripped of her silver medal, and North Korean shooter Kim Jong Su whose silver and bronze medals were revoked.

Three of those nine cases are still under appeal at the Court of Arbitration for Sport (CAS) in Lausanne.

Belarusian hammer throwers Vadim Devyatovskiy and Ivan Tsikhan were stripped of their silver and bronze medals after testing positive for abnormal levels of testosterone.

Their hearing dates have yet to be scheduled.

Polish canoeist Adam Seroczynski tested positive for the anabolic agent clenbuterol after finishing fourth in flatwater K2.

His appeal was heard last month and a CAS ruling is expected within weeks.

A further six positive drug tests on horses were returned in the Olympic equestrian events.

One case is pending at CAS to decide the bronze medal in team jumping.

Tony Andre Hansen, a member of the third-place Norway team, appealed after his horse Camiro tested positive for a banned pain-killing medication.

Fourth-place Switzerland is in line for bronze.