The Charity Commission has contacted Oxfam after being made aware that the charity was dealing with a number of what the regulator called "concerning allegations" made against senior staff, including claims of sexual harassment.
The charity said it dealt with 87 allegations of sexual abuse by staff in 2016/17, of which 53 were reported to police and other services, 33 were investigated internally and one was still pending.
Of those investigated internally, three-quarters were upheld and resulted in disciplinary action, the charity said.
The commission is understood to have begun looking into the charity after The Times newspaper approached it for comment last week about claims that a former Oxfam manager was sacked after she made a complaint of sexual assault against a senior colleague.
Lesley Agams was dismissed as the charity’s country director for Nigeria in 2010, three months after she accused a senior manager of sexually assaulting her at a hotel during an Oxfam conference in Oxford, The Times reported.
The charity said today it had thoroughly investigated the case at the time but could not uncover enough evidence to substantiate it. But it said it was sorry for the distress that the handling of the case caused Agams and said it believed it would deal differently with the complaint today.
"Oxfam treats all complaints of misconduct very seriously and systems are in place to ensure they are handled properly," said an Oxfam statement. "Our internal procedures were followed in this instance and Ms Agams was given support and advice once we were made aware of the allegations.
"Like many organisations, we continually seek to improve our procedures and practice on safeguarding. We have worked hard in recent years to raise awareness among all staff and have a confidential whistle-blowing helpline, a dedicated safeguarding team, and safeguarding focal or contact points within countries."
The commission said today that it had been in contact with the charity to establish how its trustees were dealing with the individual allegations.
"We have become aware that Oxfam is dealing with a number of concerning allegations about both recent, and non-recent, safeguarding incidents involving senior staff, including allegations of sexual harassment," the regulator’s statement said.
"We are in contact with the charity to establish both how the trustees are responding to the individual allegations, as well as to reassure ourselves that they are taking steps to ensure the charity is appropriately safeguarding all people who come into contact with it, including its staff and volunteers."
The charity also said its work to inform staff about how they could make complaints in confidence had resulted in more people coming forward.
"Oxfam is not unique," the charity’s statement said. "Sexual abuse is a serious problem in society. We all, including Oxfam, need to get better at preventing and dealing with sexual abuse but as an international organisation fighting for women’s rights we have a special responsibility to practice what we preach and protect our staff, volunteers and beneficiaries from sexual harassment and abuse."
The commission said that that any incidents or allegations of abuse or harassment within charities risked undermining a charity’s reputation and public trust in charities generally, particularly if they were not properly handled.
"Trustees must be mindful of this and take steps to ensure their charity safeguards all people who come into contact with it, including its staff and volunteers," the regulator’s statement said.
"They should foster a culture that promotes the wellbeing of their staff and must put in place robust safeguarding procedures and ensure these are followed in practice.
"Such procedures should cover how the charity responds to individual allegations of harassment or abuse, including by reporting them to the police where appropriate, and to consider reporting them to the commission as a serious incident."