Dr Wade Exum sued the USOC in July, claiming its leaders sabotaged the anti-drug battle it hired him to wage and discriminated against him because he is black.
The USOC has moved for some of the claims to be thrown out, saying they were made under state law. They have asked a federal court in Denver to dismiss them
But Exum said his original complaint contains enough evidence of wrongdoing to let the suit proceed.
Race discrimination claims
He claimed the USOC evaded its responsibility to screen and discipline athletes for drugs in its quest to produce medal-winning competitors.
The USOC responded separately to the race-discrimination claims and has not moved to dismiss them, Exum's lawyer, John McKendree, said.
Exum resigned in June after nine years as director of the USOC's Drug Control Administration.
In their response to the dismissal motion, Exum's lawyers on Friday said he was publicly portrayed in a false light, wrongfully fired and victimised by fraud and breach of contract.
They claimed "the USOC has fouled his reputation by placing his name at the top of a system that, beyond his control, encourages the use of dangerous, illegal drugs by athletes."
USOC officials were still in Sydney after the Olympic Games or were on their way back on Tuesday, and could not be reached for comment.
A former USOC medical chief alleged in a sworn affidavit filed Friday that U.S. Olympic athletes commonly used banned drugs and the USOC covered up positive tests.
Dr Robert Voy, chief medical officer from 1983 to 1989, also said the USOC had no interest in curbing the use of such drugs. He said its doping program encouraged the use of performance-enhancing drugs.
At the time, a USOC official said Exum had offered to resign nine months earlier, saying he would not sue the organisation on condition that it paid him US$5.5 million.
