By Karolos Grohmann
LONDON (Reuters) - Doping moved back into the spotlight at the London Olympics on Saturday with at least two more confirmed positive cases and a string of high-profile doping offenders returning to the world's biggest sports stage in search of restitution.
On the day when athletics, the flagship sport of the Games, took centre stage with its big names starting their quest for gold, Colombian 400 metres runner Diego Palomeque Echevarria became the latest athlete to be banned following a positive first test for performance-boosting testosterone.
Scheduled to run on Saturday morning, he was temporarily suspended pending a B sample test, the International Olympic Committee (IOC) said on Saturday.
He joined Russian cyclist Victoria Baranova, who was sent home for failing a test for testosterone, to bring the tally of athletes suspended by the IOC to four since the start of the Olympic period on July 16.
Several other athletes, including Brazilian rower Kissya Cataldo da Costa who was expelled on Saturday for failing a dope test for EPO, have been sent home by their own federations.
"I do not think this changes where we are at all," IOC spokesman Mark Adams told reporters, when asked whether the latest positive tests were showing a wider use of banned substances at the Games than expected.
"Cheats are being caught and ejected," he said. "At this stage it is a pretty low number."
Ironically, it was also the day when former big name doping offenders Justin Gatlin, Dwain Chambers and LaShawn Merritt made their Games comebacks in front of an enthusiastic 80,000 crowd.
"I would clearly rather have that these competitors are not here," Games chief Sebastian Coe told Reuters.
"The federation says they are eligible to compete, the IOC says they are eligible to compete so we give them as much courtesy as all the other athletes."
"The answer is that that is the world we live in," said Coe who said he wanted to have a four-year ban for first time offenders rather than the current two years.
"I am sorry my sport has moved from four to two years," the former two-time Olympic 1,500 metres champion said. "I don't think that this is a sufficient deterrent."
Briton Chambers, once the face of doping, needed to overrule a British lifetime ban for drugs offenders to win a spot on the Games.
While his comeback after suspension a few years ago was greeted by jeers and boos, he received a raucous welcome from a home crowd.
"More than anything, it's just a great feeling to know that when you've had upsets in your life, if you still remain focused and believe in yourself anything can happen," he said after winning his heat in style.
Gatlin, the 2004 Games 100 metre gold medallist, and back for his first Games after serving a four-year doping ban, was even more dazzling with 9.97 seconds in the second heat of the first round.
"I had a couple of tears before I got on the track," he said. "It's good to be back."
Merritt, the 2008 Olympics champion in the 400 metres, also made his comeback. He was less lucky though, dropping out of his title defence after only a few seconds due to a hamstring injury picked up last month.
He served a 21-month drugs suspension for using of an over-the-counter male enhancement product in 2010 that contained the banned substance dehydroepiandrosterone (DHEA) and pregnenolone.
There was no intention to dope and nor to gain a competitive advantage, an international panel found.
(Editing by Alison Williams)