When I read the revelations that Oxfam workers had paid for sex in Haiti, perhaps from underage girls, while the country was trying to recover from an earthquake, I wasn’t surprised. Nor was I surprised when it became clear that it had been covered up, and that further allegations of sexual abuse, bullying, harassment and intimidation in the aid sector soon followed. Don’t get me wrong – these stories are sickening – but most people in the industry will have at the very least heard rumours of this kind of behaviour.

I spent more than 15 years as an aid worker specialising in communications for a number of organisations, including Oxfam, where I worked for five years as an emergencies communications specialist and media coordinator. My work took me from Haiti, Syria and Lebanon to Bangladesh, Tajikistan and Jordan. I had the privilege of meeting incredible people and worked with some brilliant people, as well as some not so brilliant.

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There was a culture where bullying was rife, women were frequently belittled and racism was casual. And it was not just at Oxfam. This happened in many organisations I worked for in the sector. Every time I clearly identified a problem, I was made into the problem.

When I went on record with HR in Oxfam and other places to tell them about my experiences, nothing was done. I learned over the years how similar the cultures in these organisations were. There is a revolving door between many of them, so men who have been marked out by women as “not nice” go from one agency to another. It’s not a coincidence that most of Britain’s biggest aid NGOs are dominated by white men and some white women at a senior level. Women have described it as “bro” culture.

And it’s not just me. Over the past year, I have been in touch with women working for aid institutions who have told me about their experiences of sexual harassment. I contacted women in the sector after co-founding Intersectional Feminist Foreign Policy – a platform seeking the creation of a foreign policy that does no further harm to women and girls around the world. This includes wrongdoing by UN peacekeepers and aid workers accused of sexual exploitation and abuse of vulnerable women and girls.

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The culture of silence runs deep – the usual fears that prevent women and whistleblowers from speaking out apply here (for example, the UN whistleblowers in Haiti received anonymous threats). But there is an added stigma in the aid world. There is a fear that if we tell the truth, the reputational damage to the agencies will benefit the sections of the press and politicians who want to reform the sector.

To the CEOs running aid organisations and the board members put in place to hold them to account, the message is simple: don’t shoot the messengers. Take responsibility for what has gone on and continue to do so, and work towards reforming an industry that is in urgent need of change if it is to tackle the root causes of these endemic problems.

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Thanks to brave whistleblowers and those who have confronted Oxfam, many of whom are women, the floodgates are now open. It will be impossible to hold back all the information emerging from other aid organisations on the opaque and damaging cultures that have allowed potential criminal activity, sexual exploitation, harassment and other abhorrent behaviour to thrive, and indeed be rewarded through the promotion of those accused of wrongdoing. We have seen at least one resignation – there may be more.

Since the Oxfam revelations last week, more women have contacted me. They are unleashing a silent and controlled rage. Almost every woman I speak to will not reveal their name for fear of career reprisals or fuelling the war against the aid sector, as calls increase to cut off funding to UK aid organisations. This is clearly not the answer, as the sector does so much important work. But it needs a properly funded independent organisation to investigate claims of sexual harassment and abuse. Aid agencies must not be left to carry out their own investigations. Women need to know they will be believed and not victim-blamed for problems caused by a privileged few.

• Shaista Aziz is a standup comedian and former aid worker. To get in touch with her, email her here