A spokeswoman for Harvard, Rachael Dane, said that the university was unaware of the circumstances surrounding the sale until asked about it by The Globe, and that it was now conducting an independent review.

“We are committed to ensuring the integrity of our recruitment practices,” she said.

Ms. Dane would not confirm whether Mr. Zhao’s younger son was in fact recruited by Mr. Brand, although the brothers were referred to as student-athletes in the email sent to students and faculty members on Thursday.

In the email, Claudine Gay, the dean of the Faculty of Arts and Sciences, wrote that Harvard’s athletic recruitment practices were different from those of some other schools. The applications of student recruits are reviewed by the full admissions committee, which has roughly 40 members, and admissions decisions are made by a vote of the whole committee. Also, she said, all recruited athletes had to be interviewed by an admissions officer or alumni interviewer.

At this stage of the investigation into Mr. Brand, she said, there was a lot the university did not know yet.

“Regardless of what we eventually learn about these allegations, this is not a time for complacency,” she wrote. “Where there are opportunities to clarify practices and strengthen procedures, we must act on them, and do so with a sense of urgency.”

The university’s admissions practices have been under scrutiny for months. A lawsuit charging Harvard with discriminating against Asian-American applicants went to trial in October. In the process of defending itself, Harvard was forced to reveal many admissions secrets, including the advantages given to students whose parents went to Harvard, relatives of donors and recruited athletes. Documents showed that in recent years the admission rate of recruited athletes was 86 percent. A judge has not yet ruled in the lawsuit.

The Globe also reported on another set of peculiar transactions involving Mr. Brand, Mr. Zhao, and a nonprofit organization called the National Fencing Foundation of Washington D.C.