The head of one of Britain’s biggest charities resisted calls to resign on Wednesday after a damning inquiry into the organisation’s handling of allegations of sexual harassment and inappropriate behaviour against senior managers.

A Charity Commission investigation into Save the Children’s handling of claims against Justin Forsyth and Brendan Cox, respectively the charity’s former chief executive and policy director, will be published on Thursday.

But leaked details of the inquiry, published in the Times, in which the commission accused Save the Children of “serious failures and mismanagement” of the way it dealt with the allegations in 2015, led to calls for the resignation of Kevin Watkins, the charity’s chief executive.

The inquiry found “serious weaknesses” in the charity’s workplace culture and said that, when the claims became public in February 2018, the organisation issued statements that were “not wholly correct” and was “unduly defensive” in its response, reports said.

Save the Children has been mired in allegations that it failed to investigate claims of sexual harassment and inappropriate behaviour by Forsyth and Cox. Although three complaints were made about Forsyth’s “inappropriate behaviour” at Save the Children, his next employer, Unicef, was not informed.

Watkins, who was a trustee at the time of the 2015 allegations and went on to become CEO of the charity, has said the organisation has since reformed its process for providing staff references. He also said he regretted talking to headhunters involved in Forsyth’s recruitment to Unicef.

The Conservative MP Pauline Latham, a member of the international development committee who questioned Watkins in parliament in 2018, accusing him of being part of a “cosy boys’ club”, said he should resign.

Watkins has been criticised by MPs for spending £114,000 on lawyers to try to stop reports of inappropriate behaviour coming out in the media, after the full story emerged in 2018.

Cox, husband of the murdered MP Jo Cox, was suspended following sexual harassment allegations in 2015. He was investigated and a disciplinary panel set up, but resigned before it could hear the case. In 2018, when the scandal became public, he resigned from the two charities he set up after being publicly accused of sexual assault. He denied the claims of assault but admitting making “mistakes” at Save the Children.

Forsyth resigned from Unicef in 2018 after it emerged that three female staff members at Save the Children had accused him of inappropriate behaviour between 2011 and 2015.He said he was not resigning because of the “mistakes” he had made at the charity, for which he had apologised unreservedly at the time, but because of attempts to damage aid organisations and the humanitarian sector. He said: “I want to make clear I am not resigning from Unicef because of the mistakes I made at Save the Children. They were dealt with through a proper process many years ago. I apologised unreservedly at the time and face to face. I apologise again,” Forsyth wrote.

The Times quoted the report as saying: “A charity’s reputation will usually be best served by being open, giving full and complete explanations, and not making any statement which is open to criticism as being partial or incomplete.”

The commission launched a statutory inquiry into the charity’s handling of the allegations in April 2018. The charity agreed to stop seeking British aid funding.

Save the Children chief accused of being part of ‘cosy boys’ club’ Read more

Calling for Watkins’s resignation, Latham said: “Save the Children never took these claims seriously. Now is the time to realise you can’t do that. Kevin Watkins was a trustee. He was on the inside track, he must have known the right people to get the job he got. He was wrong to spend money that should have gone to children on lawyers to try and stop reports of this coming out. Anyone tarnished with that reputation should go.”

Alexia Pepper de Caires, who worked at Save the Children between 2011 and 2015, and has since set up the organisation Safe Space in response to the safeguarding scandal in the aid sector, said: “Kevin Watkins wanted to keep everything under wraps and spent money on expensive lawyers to do this. This caused further harm. He should take responsibility for what happened and go.”

In a statement, Watkins made it clear he would continue in the organisation.

Watkins said: “Our leadership team and board have apologised unreservedly to the women affected by the behaviour of these two senior executives. We have made progress on our workplace culture, but still have work to do to strengthen our organisation. We are determined that all our staff should live by the values of respect, compassion and integrity on which Save the Children was founded.”