Oxfam's former head of safeguarding has claimed the alleged sexual misconduct of staff in Haiti is just the tip of the iceberg, adding that one in 10 staff were affected by sexual assault.
Whistlebelower Helen Evans says she once heard three allegations in 24 hours, but charity bosses did nothing when she raised concerns.
As Oxfam continues to reel from last week's report in The Times, alleging that staff used prostitutes following Haiti's 2011 earthquake and that Oxfam covered up the results of its internal inquiry, Evans has spoken out about her own first-hand experience, first in an interview with Channel 4 and then in a lengthy statement on Twitter.
Speaking to Channel 4, she said that, in a single day, "There was... a woman being coerced to have sex in a humanitarian response by another aid worker, another case where a woman had been coerced in exchange for aid and another one where it had come to our attention where a member of staff had been struck off for sexual abuse and hadn't disclosed that, and we were then concerned about what he might be doing."
In a lengthy statement on social media, Evans said she was tasked with setting up a safeguarding function in 2012, to tackle sexual exploitation and abuse perpetrated by Oxfam staff, as "what happened in Haiti was inexcusable and the organisation sought to take action."
Her investigations revealed that "Haiti wasn't an isolated incident. There was a systematic issue with the number of safeguarding allegations, published in Oxfam's Annual Accountability Report, rising year on year from 12 in 2012/13 to 39 in 2013/14 of which 20 allegations were fully or partially upheld."
In December 2014, Evans said, she was tasked with presenting a paper to the CEO's leadership team, based on a confidential survey of staff in three Oxfam country programmes. The paper showed that one in 10 staff were reporting witnessing or experiencing rape or attempted rape.
However Evans said she was told not to attend the meeting by the CEO, adding that she subsequently submitted concerns following the three allegations of child abuse in Oxfam shops in the case of 24 hours, but was told only that management would conduct a strategic review.
At this point Evans says she resigned, "deeply concerned and frustrated that there was no serious commitment to change", before taking her concerns to the Charity Commission, which "failed to meet with me or ask for any further information."
'We failed to act'
The deputy chief executive of Oxfam has stepped down over the scandal, saying concerns pre-dated the Haiti 2011 allegations but were not followed through.
Penny Lawrence, who was programme director in 2011, said: "Concerns were raised about the behaviour of staff in Chad as well as Haiti that we failed to adequately act upon.
"It is now clear that these allegations - involving the use of prostitutes and which related to the behaviour of both the country director and members of his team in Chad - were raised before he moved to Haiti."
Oxfam's head of trustees, Caroline Thomson, has already announced that the charity's method of vetting and recruiting staff would be vetted as part of an initial raft of measures to "improve safeguarding" and strengthen the handling of sex abuse cases.
Oxfam bosses met government ministers on Monday to explain their handling of the Haiti allegations, and the Charity Commission has launched a statutory inquiry. Oxfam denies a cover-up.