Condemning Turner's "crime and actions," USA Swimming said that he is not a current organization member and is ineligible for membership.
"Brock Turner's membership with USA Swimming expired at the end of the calendar year 2014 and he was not a member at the time of his crime or since then," USA Swimming spokesman Scott Leightman said. "As a result, USA Swimming doesn't have any jurisdiction over Brock Turner."
Turner, 20, was convicted in March of the intent to commit rape of an intoxicated/unconscious person, penetration of an intoxicated person and penetration of an unconscious person.
Prosecutors had asked that Turner be sentenced to six years in prison for the January 2015 assault.
But Santa Clara County Superior Court Judge Aaron Persky
said Turner's age and lack of criminal history made a six-month jail sentence with probation more appropriate. Turner also has to register as a sex offender.
"A prison sentence would have a severe impact on him," Persky said last week. "I think he will not be a danger to others."
The outcry over a sentence seen as lenient by many was compounded by widely circulated letters to the judge from the victim and Turner's father.
The USA Swimming reaction is the latest example of a wave of national condemnation of the sentence.
"Had he been a member, he would have been subject to the USA Swimming Code of Conduct," the statement said.
"USA Swimming strictly prohibits and has zero tolerance for sexual misconduct, with firm Code of Conduct policies in place, and severe penalties, including a permanent ban of membership, for those who violate the Code of Conduct."
"Judge Persky failed to see that the fact that Brock Turner is a white male star athlete at a prestigious university does not entitle him to leniency," the petition read. "He also failed to send the message that sexual assault is against the law regardless of social class, race, gender or other factors. Please help rectify this travesty to justice."
Stanford University released a statement Monday deflecting criticism of its handling of the case. The school did "everything within its power to assure that justice was served," from immediately investigating the case to referring it to the Santa Clara County district attorney's office for prosecution, the statement said.
A probation officer has interviewed Turner because of his conviction for a felony.
Turner said he was "sorry for what he put the victim and her family through during the trial," according to the officer's report, which CNN obtained.
He told the probation officer that he "didn't want to victimize her at all," the report reads.
Turner also told the officer, "That was just my attorney and his way of approaching the case. I didn't want to degrade her in any way. I regret that. I'm sorry for her having to go through this entire process and having to even think about this for a second, all because of my actions that night. I can't believe I imposed such suffering on her and I'm so sorry."
In a searing letter read before Turner's sentencing, the 23-year-old victim described feeling "closed off, angry, self-deprecating, tired, irritable, empty" after the sexual assault.
She implored Persky
not to be lenient.
"My life has been on hold for over a year, a year of anger, anguish and uncertainty, until a jury of my peers rendered a judgment that validated the injustices I had endured," she wrote.
She told of going to a fraternity party near Stanford in January 2015, drinking and then not knowing what happened to her between the time of the party and being conscious in a hospital with pine needles in her hair. She described the traumatic and humiliating experience of enduring an hours-long forensic exam for sexual assault.
A letter from Turner's father, Dan, asking the judge to go easy on his son, also has been widely shared and criticized on social media. In it, the father dismissed his son's crime as "20 minutes of action."