Fiona McMillan and Rebecca Galbraith had already resigned on 7 December. They were working out their six-month notice periods when they were dismissed on Wednesday.
It is understood that the two directors strongly deny any wrongdoing.
CEO Fiona Noble told PRWeek that clients and staff have been informed of the dismissals and a plan is in place to cover their responsibilities.
Cohn & Wolfe saw a string of senior directors resign from the agency last year (PRWeek, 7 October 2009). At the time, CEO Noble said the resignations were 'part of the natural change in a company'.
This week, Cohn & Wolfe appointed Anthony Moore to be head of consumer. Moore joins from Incredibull Ideas, where he is a director.
Cohn & Wolfe has also appointed Ed Fleming as an associate director, who will focus on home entertainment accounts and report to Moore. Fleming joins from Way To Blue.
Both Moore and Fleming will join the agency in February.