Dame McCall is appearing before the government’s Culture, Media and Sport Committee, to answer questions about ITV’s approach to safeguarding and complaint-handling after Schofield left as host of This Morning.
The 61-year-old chief executive said told MPs the “imbalance of power, the imbalance of dynamics” made the relationship between Schofield and a younger colleague on the show - named in the hearing only as Person X - “deeply inappropriate”.
She assured ITV would have taken action, but said the affair had been denied by both parties, and no evidence of the relationship appeared during an ongoing investigation.
Dame McCall said she first became aware of rumours of the affair in February 2020, when Schofield publicly came out as gay, and “speculation and rumour” began to swirl.
“We started looking at it in December 2019, but it ramped up...the noise out there ramped up in February 2020,” she said.
“We worked very very hard for many many months in fact until recently to ask people - not just Phillip Schofield and Person X, but people in production - if they knew something was going on.
“It was repeatedly denied by both individuals, but also no one in the team said every said there was anything that they could say...in fact most of them said ‘we don’t know what’s going on’.”
She went on to say staff could have contacted ITV’s anonymous, externally run helpline “at any time”, but nobody did and bosses received no evidence of the rumoured relationship.
“If any one of the individuals you have named or referenced had come to us and said ‘there’s evidence of a relationship between Phillip Schofield and Person X’, with evidence we would have been able to launch a formal investigation,” said Dame McCall.
“Because the imbalance of power, the imbalance of dynamics in that relationship makes it deeply inappropriate, and we have policies that say that very clearly.
“If we’d had any formal evidence we’d have done an investigation. It’s not in our interest in any way not to investigate something that we know has evidence to support it.”
She added that she had concerns launching a formal investigation “with no legal reason” could have caused “a huge amount of damage”.
“The mental health issues around the strain - the psychological strain - on Person X etc would have been quite intense,” she said. “And so we didn’t have any legal grounds to do that.
“Nobody here or on the management board would ever turn a blind eye to something as serious as this.”
Schofield, 61, resigned from ITV and was dropped by his talent agency YMU after admitting to an affair with a younger male colleague on This Morning, which he described as “unwise but not illegal”. Since his resignation, This Morning has since been plagued with allegations of “toxicity”.
The show’s former resident doctor, Dr Ranj Singh, hit out at a “toxic” culture, saying he raised concerns about “bullying and discrimination” two years ago when he worked there – and afterwards felt like he was “managed out” for whistleblowing.
Dame Carolyn wrote a letter to culture secretary Lucy Frazer, DCMS Committee chair Dame Caroline Dinenage and Ofcom’s chief executive Dame Melanie Dawes, to confirm ITV had instructed barrister Jane Mulcahy KC of Blackstone Chambers, to carry out an external review of the facts following Schofield’s departure.
In her letter, Dame Carolyn said that an external review conducted following a complaint made by Dr Ranj found “no evidence of bullying or discrimination”.
Dame McCall is facing questions from MPs on Wednesday alongside ITV managing director Kevin Lygo and general counsel and company secretary Kyla Mullins about the This Morning row.
The committee hearing will cover ITV’s initial investigation into rumours regarding Schofield, the ITV-commissioned review into the facts by barrister Jane Mulcahy KC, the working culture on This Morning and other productions, as well as ITV’s use of non-disclosure agreements (NDAs) and its whistleblowing policy.
The broadcaster’s approach to its duty of care, including support for those who have left the organisation, is also being discussed with the panel on Wednesday.