An "actor working for a TV production company" appeared as a guest on the show earlier this week, claiming to be Fame Daddy CEO Dan Richards.
The broadcaster has now launched an investigation after its audience was "deliberately misled by this stunt". It said those behind the incident "clearly went to great lengths to pull the wool over the eyes of the programme and our audience".
"They also managed to convince other media, appearing on radio and in newspapers," the statement said.
"We carry out a range of checks, which in this case included verifying that this company was legally registered, and we did the interview in good faith."
This Morning host Holly Willoughby said on yesterday's show: "There was something not quite right, it was so unbelievable."
ITV insisted it makes "every effort to ensure the legitimacy" of the items featured on This Morning, "as well as the authenticity of all guests".
'Fame Daddy' had claimed to offer celebrity donors from the "worlds of sport, entertainment and finance - all leaders in their fields, with a proven track record of success".