Madisyn Cox, world champion swimmer and former University of Texas and Lubbock High swimmer, sued Cooper Concepts claiming their multivitamins led to her suspension from competition.

According to the Associated Press, Cox was suspended after she tested positive for an illegal stimulant. She was then forced to miss several major events.

Cox eventually had a lab conduct testing, which found the stimulant in the Cooper vitamins she had been taking.

Cox sued Cooper Concepts on Monday, saying that it was the vitamins that caused her to fail the drug test.

The company says that it was "saddened and disappointed" for Cox and "immediately removed" the vitamins from its product line last year after learning of the issue.

Cox currently ranks first in the US in the 200 meter Individual Medley.