Justin Forsyth, the former chief executive of Save the Children, has admitted to sending inappropriate text messages to junior female members of staff during his time at the charity.
Forsyth issued apologies to three women after investigations in 2011 and 2015 of messages he sent them while leading the charity, according to Save the Children.
Forsyth was chief executive of the charity between 2010 and 2015.
The messages allegedly made comments about how they looked, what they were wearing and how he felt about them, BBC Radio 4’s PM programme reported yesterday.
If the women ignored the messages, PM reported, he would email the women, asking if they had seen the messages and, if they did not respond to those emails, they would be invited into his office.
Forsyth stepped down as chief executive in 2015 and is currently the deputy executive director of Unicef.
In a statement, Save the Children said concerns raised in 2011 and 2015 about inappropriate behaviour and comments by Forsyth had resulted in two trustees carrying out two separate investigations into a total of three complaints made by three female employees.
"Both reviews resulted in unreserved apologies from the chief executive," the statement said.
But after the apologies were made, said the statement, "concerns were raised with trustees that matters should not have been left as they were".
Forsyth left the charity shortly after the charity’s policy director, Brendan Cox, resigned. Cox was being investigated by the charity for sexually harassing female colleagues at the time of his departure.
Last Sunday, The Mail on Sunday newspaper reported separate allegations against Cox dating from 2015, reigniting media interest in the Save the Children allegations. Cox has since resigned as a trustee of the charity he set up in memory of his murdered wife, the MP Jo Cox.
In response to reports about Cox’s behaviour, Kevin Watkins, who was appointed as chief executive of Save the Children in 2016, pledged to conduct a review of the charity’s system for dealing with complaints about workplace behaviour.
After the PM story about Forsyth emerged, a spokesperson for Save the Children said: "We apologise for any pain these matters have caused and sincerely hope that the complainants feel able to help us with the review in the coming weeks."
The review would begin this week and a report would published in June 2018, the spokesperson said.
Forsyth’s current employer, Unicef, said in a statement: "We welcome Mr Forsyth's decision to come forward and acknowledge past mistakes. We are discussing this matter with Mr Forsyth and his former employer so we can take appropriate action."
Third Sector was unable to contact Forsyth for comment, but in a statement to PM he said: "I made some personal mistakes during my time at Save the Children.
"I recognise that on a few occasions I had unsuitable and thoughtless conversations with colleagues, which I now know caused offence and hurt."
He said he had "apologised unreservedly" to the three colleagues, his apology had been accepted and he "had thought the issue closed many years ago". The concerns had been handled through mediation rather than a formal complaints process, he said.
He said he had played no part in the disciplinary proceedings against Cox.
A Charity Commission spokeswoman said it had engaged extensively with Save the Children in 2015 and 2016 about alleged misconduct and inappropriate behaviour by two senior executives.
After an independent review by trustees of the charity's systems, complaints handling and organisational culture, the commission made several recommendations to the charity, which the trustees had accepted, the spokeswoman said.
"We are therefore now urgently demanding further information and assurances from the charity on the scope of this new review," she said.