BEIJING - Organized doping is likely behind a recent spate of positive drug tests in Greek sports, the president of the country's Olympic Committee said Monday.

"There are 15 people, all with the same substance. This is the strangest thing, because it leads to the conclusion that there is an organized effort," Minos Kyriakou told The Associated Press.

The athletes -- 11 weightlifters, three runners and a swimmer -- all tested positive for methyltrienolone, a banned steroid.

"There is an organized crime -- because that is what this is called," Kyriakou said. "Because it seems there is a lot of money hidden there, a lot of profit."

The Hellenic Olympic Committee president stopped short of making a direct accusation as to who could be behind a system of doping, but said the state must crack down on the practice.

"I am neither a policeman nor a detective nor a judge," Kyriakou said. "I don't have that knowledge, and I think that the time has come for the state to (do something) and find a solution. I believe that if they want to, they will find it. And I believe they do want to."

In the latest embarrassment for Greece, reigning women's 400-metre hurdles champion Fani Halkia was sent home from Beijing on Sunday, hours before her scheduled heats, after testing positive for methyltrienolone. Her test was conducted by the World Anti-Doping Agency at a Greek team training camp in Japan on Aug. 10.

The scandal broke in Beijing on Sunday, the day that Greece won its first three medals -- silver in men's rowing and a bronze each in women's sailing and women's triple-jump.

Halkia denied any wrongdoing, telling Greek reporters in Beijing she was "shocked" that she had tested positive.

But Kyriakou had harsh words about the athlete.

"I don't talk about dead people," he said. "Whoever does such things, gets mixed up in such things, commits suicide. And when someone wants to commit suicide, nobody can stop them."

The 11 weightlifters, who not been named publicly, tested positive for methyltrienolone months before the Olympics, and the steroid was also found in tests on swimmer Yannis Drymonakos, 400-metre runner Dimitrios Regas and sprinter Tassos Gousis.

"Of course it has to be organized, when there are so many cases with the same substance," Kyriakou said.

The HOC president said the problem of doping was likely to be widespread.

"I believe these substances are given in most sports," he said, adding that they were likely "supplied to the naive, because someone who knows that this could lead them to death doesn't try it."

The IOC is conducting a record 4,500 doping tests in Beijing, up from 3,600 in Athens.

Greece had hoped this year to avoid the embarrassment of four years ago, when two of its brightest track stars, sprinters Katerina Thanou and Kostas Kenteris, missed drug tests on the eve of the Athens Games. The two pulled out of the Games and said they had been involved in a motorcycle accident, but have since faced allegations in court that the crash was faked.

The IOC barred Thanou from competing in Beijing on the grounds that her actions had brought the Olympic movement into disrepute.

Greek sports minister Yiannis Ioannidis, speaking during a news conference in Beijing on Monday with Greece's new medal winners, said the IOC was targeting the country's athletes because of old transgressions, but that Greece had given it the right to do so.

"As for Fani, it is a fact that they went after her. I love Fani very much. It was wrong for her to allow those who fought her to be vindicated," the minister said.

"I don't hide it at all. We are the ones who are giving this right. We gave the right, we are paying for old sins. ... For this reason, the IOC is indeed chasing us. It is a fact that they are chasing us," Ioannidis said, acknowledging that it was the job of the IOC and WADA to go after drug cheats.

Halkia was the fourth athlete to be expelled from the Games. North Korean shooter Kim Jong Su was stripped of his silver and bronze medals after testing positive for a banned betablocker, Spanish cyclist Isabel Moreno was expelled after testing positive for EPO, and Vietnamese gymnast Thi Ngan Thuong Do was caught using a prohibited diuretic.

Kyriakou said the IOC was cracking down on doping across the board.

"I don't believe that the IOC has us in its sights or is after us," he said. "If we have done what we have done, we can't accuse anyone. ... Can this thing stop? Then we'll be the best. I believe in the ability of the Greek athletes without these substances."