He has been suspended on full pay while GMTV managing director Christopher Stoddart carries out an investigation.
A GMTV spokeswoman said if the investigation revealed that other members of the production were involved it could lead to further suspensions.
However, she stressed that presenter Kelly did not know the guest was a fake.
This is the second false guest scandal to hit ITV in six months. In February Trisha, produced by United Productions, was accused of using fake guests, but both United and ITV said the show's producers had done so unknowingly.