Phillip Schofield's ex-lover is said to be able to "have his say" in the ITV probe amid claims he denied the affair.
The young runner, who is now in his twenties, is set to be quizzed by independent barrister Jane Mulcahy KC following his relationship with the former This Morning star.
It comes as part of ITV's external investigation into the scandal after Phillip quit both the show and broadcaster when he admitted to having an "unwise" but "not illegal" affair.
ITV's chief executive Dame Carolyn McCall told MPs the young man was quizzed 12 times by bosses looking into the rumours.
Yet sources close to the man have claimed it could prove "difficult reading" for ITV.
"ITV have kept in touch with the man and there will be a very thorough investigation, where many people close to the situation will be asked questions," a source told MailOnline.
They added: "It will be his chance to have his say. It could most definitely lead to some difficult reading for ITV's bosses if it turns out that he says he wasn't asked about the relationship 12 times."
Phillip sensationally quit the popular daytime show in May after admitting to the affair whilst married.
The runner had first met the veteran broadcaster when he was 15 and three years later, he started on This Morning.
Speaking in front of a parliamentary committee earlier this month, Dame Carolyn McCall argued an "imbalance of power" between Phillip Schofield and a young runner made their brief affair "deeply appropriate".
She said: "The people that have said they knew would only have heard rumours about it, if any one of the individuals you have named or referenced had come to us and said there is evidence that there is a relationship between Philip Schofield and person X, we would have, with evidence, we would have been able to launch a formal investigation because the imbalance of power, the imbalance of dynamics in that relationship makes it deeply inappropriate."
The ITV boss stated the broadcaster has "policies in place" that state this sort of relationship is inappropriate.
"We worked very, very hard for many, many months, in fact, until recently to ask people, not just Phillip referenced and person X, but people in production, if they knew something was going on," she claimed.
"And it was repeatedly denied by both individuals. But, also no one in the team ever said there was anything that they could say, in fact, most of them said we don't know what's going on."
