By Gene Cherry

EUGENE, Oregon (Reuters) - A distraught Alysia Montano called her career "a farce" and branded the International Association of Athletics Federations (IAAF) "a corrupt institution" after crashing out of the U.S. Olympic trials on Monday.

The 800 meters runner, who believes she has been denied at least three global medals by dope cheats, had hoped this would be the year she finally made the Olympic podium.

But with less than 100 meters to go in Monday's final she became entangled with Brenda Martinez and fell to the track, eventually finishing dead last.

That ended any hope of her going to Rio since only the top three finishers in the cut-throat trials advance.

Tears flowed from the 30-year-old defending U.S. champion as she spoke to reporters and the agony only intensified after she was asked why this had been such an emotional year.

"I'm missing three medals in like eight years of my life as a professional runner," said Montano, who believes she lost medals because of cheating rivals at the 2011 and 2013 world championships.

Fifth at the 2012 Olympics, Montano has since seen both winner Mariya Savinova and bronze medalist Ekaterina Poistogova, both Russians, accused of doping by a World Anti-Doping Agency (WADA) report.

"My entire professional career has been a farce basically," said the emotional Montano

"Now everyone is talking about the Russians not running in the Olympics but they are missing the whole point that the IAAF is a corrupt institution which is still running the game for us professional athletes."

The IAAF was not immediately available for comment.

The former president of the sport's global governing body, Lamine Diack, has been accused by French investigators of receiving over 1 million euros ($1.09 million) in bribes to cover up positive doping tests.

Diack's son Papa Massata Diack, a former IAAF consultant also embroiled in the case, has denied any involvement in bribery or corruption and says his father is also innocent.

The IAAF has also called for Russian athletes to be banned from the Rio Games after a WADA report unearthed what it alleged was evidence of systematic state-sponsored doping.

Emotionally, it had all been difficult to cope with as she chased a spot in Rio, Montano said.

"Trying not to take that anger with me to today and still try to be in the sport, knowing that who's been running the show have been using us all along. That's why it was an emotional struggle for me," Montano said.

"And I made it all the way to the final, with all that emotional baggage."

(Editing by Nick Mulvenney)