SHANGHAI, CHINA - Chinese race walker Song Hongjuan, who competed in the last Olympics, has been banned from competing for four years after failing a drugs test, officials said Saturday.

Song, 24, who placed 14th in the women's 20km walk at the 2004 Olympics in Athens, tested positive for erythropoietin, or EPO, at a competition in Beijing in February, a report on the Chinese Athletic Association's official website said.

The association reported the test results to the International Association of Athletics Federations and both agreed to ban Song from all competitions until March 25, 2012, the report said.

EPO increases the red blood cells, allowing blood to carry more oxygen to the body's muscles and it also helps buffer lactic acid, according to the World Anti-Doping Agency.

Song did not participate in the selection process for the 2008 Olympics, the report said.

To avoid any embarrassment while hosting the 2008 Olympics, China has cracked down on drug cheats after several high-profile doping scandals in the 1990s left their reputation in tatters.

In the first half of the year, China conducted nearly 1,400 urine tests and 80 blood tests on athletes with four proving positive. It has not identified the four, or said if Song was among them.

Beijing has also introduced tough laws that include a lifetime ban on any coach found to have given drugs to athletes.