The U.S. Anti-Doping Association has announced the two-year suspension of Brazilian-born and U.S.-licensed rider Flavia Oliveira for a doping violation committed in last year’s edition of the women’s Giro del Trentino.

Oliveira, a U.S. resident for the past 12 years, tested positive for oxilofrine, an amphetamine class stimulant. She was competing in the Giro del Trentino Donne as a member of the SC Michela Fanini team.

Oliveira’s case was heard by an independent arbitrator, Jeffrey A. Mishkin, who concluded that her violation was the result of her use of a dietary supplement known as Hyperdrive 3.0+. While recently adopted rules allow athletes who unknowingly violated doping rules to receive suspensions of less than two years, the arbitrator found that Oliveira was sufficiently at fault to warrant the full penalty.

Mishkin noted that the label on the product “lists mythelsynephrine as one of the ingredients and the parties have stipulated that mythelsynephrine is the chemical equivalent of oxilofrine.”

“While the issue is not free from doubt, the reasonable inferences to be drawn from the evidence make it more probable than not that Hyperdrive 3.0+ was the source of oxilofrine for which Mr. Oliveira tested positive,” Mishkin concluded.

However, because Oliveira waived her right to challenge the result by a test of the B sample and admitted her violation, her suspension officially began on the date her sample was taken. Her period of ineligibility will end on June 19, 2011.

To read the full text of Mishkin’s decision, click here.