In a statement, the spokesperson also said the university had "a stringent oversight mechanism involving multiple levels of internal and external scrutiny and quality checks of teaching, assessment, and marking processes".
"Drawing on data from comparable universities and programmes is one aspect of this process - to reiterate, this is a standard practice and in no way exceptional," they continued.
The Russell Group is the umbrella name for 24 leading universities across the UK, of which Queen's is a member.
The email sent to staff in the QUB Business School also included analysis carried out by a named senior staff member comparing degree grades awarded at Queen's for Business Management and those awarded in Management Studies at other Russell Group universities.
It said that while, for instance, 14% of QUB Business Management degrees were awarded the top 1st grade, around 35% of Management Studies degrees at other Russell Group universities were awarded a 1st.
"We should be considering these distributions when marking," the document said.
Concerns have been previously expressed about grade inflation at other universities in the UK.
The Office for Students (OfS) in England had previously warned English universities that they were giving too many students top degree grades.