Enter the term "FGM" in Google Images and you will find pictures related to female genital mutilation on the African continent. While the origins of FGM are murky, most experts think the practice came from Africa thousands of years ago, was later adopted by some sects of Islam and spread globally through migration.

But the truth is much more complicated. After I spent a good part of a decade travelling to research FGM around the world, I can say unequivocally that it can be found as a native practice on every continent except Antarctica. It is a global phenomenon, emerging in various places at different times, often independently.

People I have met are often surprised that I research FGM as my gender and Chinese ethnicity make me an unlikely investigator. And indeed, when I first heard about the practice in Iraq, it was by chance.

Nearly a decade ago, I started a citizen journalism project. An Iraqi NGO called Wadi invited me to do training for them, and it was then that I met Iraqi Kurds working to expose and end FGM in their country. I worked with them to produce videos that eventually were released in 2013 by the Guardian and BBC as short documentaries.

When those documentaries were released, I thought my job was done. But through Wadi, I also met other anti-FGM activists throughout the Middle East. Initially, I only thought I would make a longer documentary film about FGM in the region, but as I did more research, I realised I had to add Southeast Asian countries to the list. Then India. Then Russia. Then the United States. Eventually, my project grew to become a collection of evidence of FGM practices from around the world.

ANIMATION: What is Female Genital Mutilation (FGM)?

In my journey across continents, I have observed similar reactions among people whenever I brought up the subject. Everywhere I went, the initial reaction was always disbelief and denial. Some even discouraged me from doing research on the topic, believing that FGM wasn't practised in their community or if it were, only among minorities or immigrants.

In many of these places, FGM is a secret practice. Perhaps this is the reason why FGM has remained hidden for so long to outsiders. While many people involved in the practice or who experienced it would not talk to me, others - to my surprise - agreed to discuss it frankly on video. Perhaps the shock of a Chinese man appearing in their midst, sometimes in isolated communities such as in the Peruvian Amazon or the Russian Caucasus, made them curious and more open.

Different communities also offered different explanations about why they practise female genital cutting. In parts of Iraq, uncut females are deemed "unclean" and are not allowed to serve water. In Pattani, Thailand, female circumcision is believed to prevent diseases, including Aids. In Peru, Shipibo women were convinced uncut girls might become lesbians. In Colombia, Embera mothers would say they cut their babies to stop the clitoris from growing to become a penis.

Some Muslim sects consider the cutting mandatory under Islam, yet there is nothing about this in the Quran and many Muslims from other sects dismiss the hadith purportedly supporting the practice.

But the tendency to justify FGM extends to men of science, as well. In the mid-19th century, some British doctors believed cutting the clitoris could cure sicknesses. Another belief was that a larger clitoris was a sign of sexual depravity and that it was most commonly found among women of colour. The most prominent of the doctors who promoted FGM was Isaac Baker Brown, who in 1866, published On the Curability of Certain Forms of Insanity, Epilepsy, Catalepsy, and Hysteria in Females. In his book, he recommended litoridectomy for a number of illnesses. Although he and other similar doctors fell out of favour in Britain, their influence was far-ranging.

Their ideas spread across the ocean into the US. For nearly a century starting in the 1860s, some prominent American doctors recommended cutting the clitoris to prevent females from masturbating, which they regarded as a cause of debilitating illnesses.

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In the US, I located church and medical documents, from as late as the 1960s, that recommended the cutting. Many survivors were too young to remember the cutting and the number of elderly white FGM survivors alive in America is unknown. But there seems to be a collective societal amnesia about its practise. I found Dr Renee Bergstrom, one such survivor, and persuaded her to go public with her story. She was initially hesitant because even some people close to her were unaware of her situation. Like many other survivors, she was told never to talk about it.

But this happened not just to white American women. In Russia, a Christian sect existed until the 1920s and believed in extreme genital cutting. The Skoptsy sect, numbering possibly 100,000 members in the early 1900s, was known for male castration, but they also sometimes cut female genitals - removing the clitoris and allowing the wounds of the vagina to heal back together. They cited a passage in the New Testament, specifically Matthew 19:12 , as the reason for their cutting. In Moscow's Lenin Library, I located documents, drawings and photos attesting to their practice.

Even though FGM is outlawed in many countries, there is no shortage of clinics globally where parents can illegally bring their daughters to get cut.

FGM still exists in Russia, although it is mostly confined to the Muslim enclaves of the Caucasus. In the Russian Republic of Dagestan, once dubbed the most dangerous place in Europe, I interviewed a gynaecologist who was convinced that the "minor" female genital cutting she performs has health and sanitary benefits.

But Dr Abdulrahim Rouzi, a Saudi gynaecologist I also interviewed, believes that minor FGM could be problematic. After treating hundreds of FGM patients, he has seen that even just cutting the clitoral hood could have negative medical consequences.

Even though FGM is outlawed in many countries, there is no shortage of clinics globally where parents can illegally bring their daughters to get cut.

In my native Singapore, I posed alternatively as a British and American parent wishing to get my non-existent daughter cut and had no problems finding medical personnel willing to perform the procedure.

However, my biggest surprise during this journey was finding out how common FGM was among Singapore's Muslims and its likely detrimental impact on my own friends and extended family - people I have known for most of my life, but who had never previously spoken to me about it.

It inspired me to conduct a survey of 119 Muslim women in Singapore: 86 of them were cut; a quarter said they would continue the practice.

Indeed, FGM is not tied to a specific race or religion. Instead, religion and faulty science are used to justify why the practice is beneficial. In reality, a universal fear of sexuality, especially female sexuality, hides behind these justifications.

To be able to fight against it effectively, we have to recognise that this is a global problem and not limited to one continent or one religion.

John Chua is an associate professor at Richmond University in London. His documentary film Cut: Exposing FGM Worldwide will be released later this year.

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.