Chief of Staff Katie Telford testified at a parliamentary committee on Friday afternoon, telling members again that she did not know that accusations against General Vance were sexual in nature.
Telford said that she and Prime Minister Trudeau were not aware of the nature of the allegations until they were made public in February by media outlets.
Telford told committee that former aide Elder Marques informed her of a complaint, calling it a "personal misconduct" issue against Vance.
The chief of staff was pressed by Conservative members of the committee, including when Conservative Shadow Minister of National Defence James Dezan called on Telford to reveal if she had intentionally not told Trudeau about the allegations.
Telford would not answer, and would not reveal whose decision it was to not inform Trudeau of the allegation in 2018.
Allegations against Vance are being investigated. It is alleged that Vance had an inappropriate relationship with a subordinate, and allegations also include distasteful emails.
Controversy arose after it was found that the prime minister had given Vance a raise, despite allegations being made against him.