Save the Children promises review after claims against former CEO

In a statement Tuesday, the international charity said former CEO Justin Forsyth was investigated twice after complaints from three women about his conduct in 2011 and 2015.

On both occasions, the investigation led to "unreserved" apology from the chief executive and "the matters were closed," the statement said.

The Save the Children allegations follow outage over revelations that staff from British-based charity Oxfam abused their position of trust to engage in sexual acts with the people they were supposed to be helping.

According to the BBC, which first reported the claims, Forsyth allegedly sent inappropriate text messages to young female staff about what they were wearing and how he felt about them.

Forsyth left the charity at the end of January 2016 to take up a role as the Deputy Executive Director at UNICEF.

He's reported to have issued a separate statement Tuesday, saying he had made some "personal mistakes" during his time at Save the Children, and that he had thought "the issue closed many years ago."

"I recognize that on a few occasions I had unsuitable and thoughtless conversations with colleagues, which I now know caused offense and hurt," he said, according to the BBC.

UNICEF told CNN it is aware of the reports regarding the "past complaints" about Forsyth.

In an email, UNICEF spokeswoman Najwa Mekki said, "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."

Current Save the Children chief executive Kevin Watkins pledged a "root and branch review" of the charity's culture to check the safety of staff was being properly protected.

"The review will commence by the end of this week and report in June 2018," a spokesman for Save the Children said in a statement.

"We apologize 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. This is so that we can better support our skilled and highly valued staff as they help change the lives of millions of children around the world every day."