Complex sentence: She won gold in the women's hammer throw event at the 2004 Summer Olympics in Athens; in 2012, her samples were retested, and she tested positive for anabolic steroids; subsequently she was under investigation by the International Amateur Athletics Federation.
Split into simpler sentences: She won gold in the women's hammer throw event at the 2004 Summer Olympics in Athens. In 2012, her samples from the 2004 Olympics were retested, and she tested positive for anabolic steroids; subsequently she was under investigation by the International Amateur Athletics Federation.