The BBC has learned that Forsyth, who is currently a deputy executive director at UNICEF, faced three complaints from young female staff members, being accused of sending inappropriate texts and commenting on what they were wearing.
Forsyth confessed to having "unsuitable and thoughtless conversations" with staff for which he had "apologized unreservedly," according to the BBC.
Similar incident facing charity sector occurred after it emerged that a number of Oxfam workers paid prostitutes while working in Haiti following the 2010 earthquake. The company has been warned that it might lose millions of pounds in government funding.
The confessions come amid a series of explosive allegations against high-profile politicians, Hollywood stars and media elites, starting at the end of the previous year.