Katherine McGaffigan—the key witness whose testimony in a Boston federal court last month led to the conviction last Friday of a neo-Nazi and his white supremacist girlfriend for conspiracy to bomb a Jewish or black landmark—is not actually a Harvard undergraduate despite her claims to the contrary, the University confirmed last night.

“Kathy McGaffigan is an ALB degree candidate (Bachelor of Liberal Arts) in the Harvard Extension School, which is the school of continuing education, and is also registered as a Special Student in the Faculty of Arts and Sciences,” according to an e-mail sent last night by Dean of the College Harry R. Lewis ’68.

McGaffigan testified under oath that she is a Harvard “senior”—a claim that clashed with information provided this past week by officials from 20 Garden St. to the Barker Center.

“Our records don’t show that she’s been regularly enrolled,” said Associate Dean of the College Thomas A. Dingman ’67.

The registrar’s office said McGaffigan’s affiliation with Harvard was not as a full-time undergraduate, but as a “special student.” Special students take individual classes that do not count toward a Faculty of Arts and Sciences degree.

“One of the requirements for [special student status] usually is an undergraduate degree,” said a staffer in the registrar’s office. The information of whether or not McGaffigan had received a degree from another university was unavailable, the staffer said.

As a special student this past spring, McGaffigan enrolled in Bernbaum Professor of Literature Leo Damrosch’s popular class, English 185, “Wit and Humor.”

Megan L. McDaniel, McGaffigan’s section leader for the class, said she had “no idea” that McGaffigan was preparing to be a witness in the conspiracy case while enrolled in the class or that she had been involved in white supremacist groups.

“I’m really, really shocked,” McDaniel said. “It’s a humor class, it’s not the place you’d expect to find something like that.”

During her one confirmed semester of study at Harvard in the spring, McGaffigan did not appear to be very involved in campus life.

“She was traveling a lot,” McDaniel said. “She went to England around the time of Spring Break. It was an excuse she gave me to get out of class one time.”

Five other students in McGaffigan’s “Wit and Humor” section said they did not know McGaffigan, two of whom said they could not put her name with a face from the class.

“I don’t recall her having any friends in the class,” McDaniel said.

Harvard officials could also not confirm a House affiliation for McGaffigan. All College undergraduates are assigned to a residential House in the spring of their first year and must retain a House affiliation for the rest of their time studying at the College.

McGaffigan told The Crimson last week that she was a member of Dudley House, the one nonresidential House with which some off-campus students affiliate.

But McGaffigan has never been a Dudley member, said Dingman, who is senior tutor of the House.

McGaffigan also told The Crimson she is pursuing a special concentration in “creative writing and literature,” and a member of her “Wit and Humor” section said McGaffigan had claimed to be pursuing such a concentration.

But staff in the committee on special concentrations, as well as in the English department and in the literature concentration, all said that McGaffigan is not and never has been a concentrator in their respective fields.

“She never even applied for a special concentration,” said Stephanie Macaris, the staff assistant for special concentrations.

McGaffigan, who said she was interested in performance studies, has performed with the Exhibitionists, a women’s performance art group in New York City. This past winter she performed a “chilling monologue” titled “Holy,” said Exhibitionists co-founder Jennifer Laskey.

The case against Leo Felton, 31, and Erica Chase, 22, was based largely on the testimony of McGaffigan, their one-time associate.

McGaffigan began to cooperate with the federal investigation leading to the Felton and Chase’s conviction, while under questioning by Secret Service agents the day after McGaffigan had removed 50 pounds of ammonium nitrate—a fertilizer used in making bombs—from Felton and Chase’s apartment.

A spokesperson for the U.S. attorney’s office would not say whether or not McGaffigan had been given immunity in exchange for her testimony.

“She has not been charged with anything at this point,” said Samantha Martin, another spokesperson for the office.

McGaffigan, who could not be reached for comment this week, is the third extension school student discovered posing as a Harvard undergraduate in the past three years.

—Staff writer Stephanie M. Skier can be reached at skier@fas.harvard.edu.