Complex sentence: At the start of the 2003 season however he tested positive for nandrolone-same as Marcin Kobierski twice medalist in C-2 1000 m. Both denied the charge but were given a two-year ban which cost them a place at the 2004 Olympics.
Split into simpler sentences: At the start of the 2003 season however he tested positive for nandrolone. He denied the charge but was given a two-year ban which cost him a place at the 2004 Olympics.