A small farming town in southern Brazil — Cândido Godói, in Rio Grande do Sul — has, for the past century, produced an unusually high proportion of twins. Most of those twins are blonde and blue-eyed. In 2009 an Argentine journalist named Jorge Camarasa published a book suggesting the cause was Josef Mengele, the Auschwitz concentration camp doctor whose post-war whereabouts were never fully accounted for and who, the book argued, had continued his twin experiments in South America after fleeing Germany. The story went global within days. Geography Scout doesn’t normally touch Nazi-conspiracy material because the genre is so often shoddy; we made an exception for the original Mengele’s Twin Mystery documentary because the science of what was actually happening in Cândido Godói deserved a careful answer.
Sienna ran the historical thread. She’s spent enough years in Holocaust archive work to be cautious about how this story is told. Hugo ran the genetics. Between them, they’ve put together what we think is the honest version of what’s going on in that town, what the documentary did well, and where the conspiracy theory completely falls apart.
What Cândido Godói Actually Looks Like
The town sits in the rolling green country of southern Brazil’s German-Brazilian heartland. Most of the population descends from German immigrants who arrived in the 1850s and built farming communities that, in many ways, still feel German. They speak a German dialect — Hunsrückisch — alongside Portuguese, run their farms on a Bavarian model, and have intermarried within a relatively small founder population for over five generations. The town’s twin rate, according to a 2011 study by geneticist Ursula Matte and colleagues, runs at about 10% of all births — roughly six times the global average.
The people who live in Cândido Godói know about the rumour. It has been a tourist draw, and not always a welcome one. The municipal museum has a section dedicated to the twins and a wall noting, in plain language, that the Mengele theory has no supporting evidence. The town would much rather you came for the scenery and the food. Sienna’s read of the town’s own self-presentation: they’re tired of the Nazi angle. We’d have been tired of it too.
The Conspiracy Theory in Brief
Camarasa’s 2009 book Mengele: el Ángel de la Muerte en Sudamérica alleged that Josef Mengele, who is documented to have lived in Brazil from 1962 until his death in 1979, made repeated visits to Cândido Godói in the late 1960s and early 1970s. He was supposedly known to locals as “Senhor Rudolph” or “Senhor Alemão” and posed as a vet, a homeopath, or an itinerant doctor. The theory holds that he ran some form of intervention — hormonal treatment, IVF-adjacent technique, or selective breeding programme — that produced the elevated twin rate.
The documentary picked the story up sympathetically and did some real journalistic legwork. Production crews interviewed locals, the historians in São Paulo and Buenos Aires who’d worked on Mengele’s post-war movements, and the geneticists who’d studied the twin clusters. Where the documentary deserves credit, and where most subsequent coverage of the story did not, is that it gave the genetics team substantial airtime to walk through the actual evidence.
What the Genetics Says
Hugo’s summary, distilled: the twin rate in Cândido Godói is real, well-documented, and almost certainly caused by genetic founder effects rather than any external intervention.
The 2011 Matte study, published in PLOS ONE, sequenced DNA from twin pairs in the town and from a control group elsewhere in Brazil. It found a high frequency of a specific genetic variant — a mutation in the p53 tumour suppressor gene — among the twin mothers. That same variant has been associated with elevated dizygotic twinning rates in other founder populations. It’s a heritable trait. The Matte team also found that the twin clusters had been showing up in church records since the late 19th century, decades before Mengele was born. The twin rate didn’t spike during the period he was supposedly visiting; it has been roughly stable since the German immigrant generation arrived in the 1850s.
That last point is decisive. If Mengele had caused the twinning, you’d expect the rate to rise sharply in the 1960s and decline afterwards. Instead, it’s a steady multi-generational signal that pre-dates his presence in Brazil by half a century.
Where Was Mengele, Really?
Mengele’s post-war movements have been reconstructed in considerable detail by historians, journalists, and Mossad investigators. After fleeing Germany in 1949 he went first to Argentina under a false identity, then to Paraguay in 1959, and finally to Brazil in 1962. His Brazilian years are documented through the diaries he kept (now archived in São Paulo state), through correspondence with the Stammer family who hosted him, and through the police investigation following his death by drowning in 1979 at the beach town of Bertioga.
None of those documentary sources place him in Rio Grande do Sul, let alone in Cândido Godói. He spent his Brazilian decade and a half in São Paulo state and the southern coast — about 1,000 km from the twin town. Local witnesses in Cândido Godói describe a German-speaking visitor who matched Mengele’s general age and demeanour, but Hunsrückisch-speaking German immigrants were by no means rare in 1960s southern Brazil. Sienna’s read: the eyewitness accounts are credible as memories, but the identification of the visitor as Mengele specifically is not. The most likely explanation is mistaken identity reinforced by retrospective storytelling after the conspiracy theory went public in 2009.
Why the Story Keeps Travelling
Conspiracy theories that combine genuine atrocity, hidden continuation, and a small isolated community where the evidence appears to be visible on the streets are durable in a way that the simple historical record is not. Cândido Godói genuinely is unusual. Mengele genuinely was a monster who genuinely escaped justice. The twins genuinely look German. Each of those is true on its own. The conspiracy welds them into a narrative the brain wants to accept because each individual piece is undeniable — and you have to pay attention to notice that the welding doesn’t actually hold.
The deeper reason the story persists, Sienna argues, is that it does the work of moral closure. Mengele died of a stroke at sixty-seven, swimming at a beach, never having faced trial. That is intolerable to anyone with a sense of justice. The Cândido Godói theory turns him into someone who continued his crimes and was therefore, in a way, never quite gone — a ghost that needed exorcising. The actual genetics, with its founder mutations and sober p53 alleles, doesn’t satisfy that emotional need. So the conspiracy keeps coming back.
What the Documentary Got Right and Wrong
The 2009 documentary handled the material more carefully than the trade press of the time gave it credit for. It interviewed both sides — the Camarasa camp who believed in the Mengele theory and the Brazilian and German geneticists who’d done the population work. It refused to commit one way or the other in its narration, which our team thinks was the right editorial decision given the evidence at the time of broadcast.
Where it was weaker: the visual grammar. The producers couldn’t resist intercutting the German-Brazilian children’s faces with archival Auschwitz footage, which is a kind of editorial assertion the script itself never made. We’d argue the cut undermined the show’s own commitment to even-handedness. Hugo flagged a second issue: the genetic explanation was given less screen time than the sensational angle, which is the standard distortion of factual television. By minute count, the conspiracy theory got two-thirds of the runtime; the actual answer got the rest. That’s roughly inverted from where the evidence sits.
What the Best Recent Scholarship Says
The 2024 follow-up paper by the Matte group at the Federal University of Rio Grande do Sul reinforced the founder-effect explanation with deeper sequencing. They identified additional candidate variants on chromosome 17 that fit the pattern. There’s also strong epidemiological evidence that the high twin rate is concentrated in specific extended families within the town, exactly as you’d expect from a heritable trait. Conversely, there is no peer-reviewed evidence — none — supporting the Mengele intervention theory. Camarasa’s book remains uncorroborated by any historical or genetic source.
For readers who want to chase this further, the best single source is the PLOS ONE paper itself (Matte et al., 2011, “Population, religion and ethnicity”). For the historical Mengele, Gerald Posner and John Ware’s Mengele: The Complete Story (1986) remains the gold-standard biography. For the broader question of how Nazi war criminals dispersed across South America after 1945, Uki Goñi’s The Real Odessa (2002) is the most carefully sourced English-language treatment.
A Note on Tone
One of the things we try to do at Geography Scout is take stories like this seriously without amplifying them. The Cândido Godói twins are real people, mostly now adults, many of them tired of being treated as a curiosity. The town has been visited by film crews and tourists for over fifteen years now and has seen a steady stream of bad coverage that flattens its real history — German immigration, founder genetics, generations of farming life — into a single Nazi-shaped headline. The honest version of the story is more interesting and more humane than the conspiracy version. That’s almost always the case.
If you’re teaching genetics, the case is a usefully clean illustration of founder effects in small populations. If you’re teaching media literacy, it’s a clean illustration of how a sensational hypothesis can survive even when the supporting evidence is decisively absent. And if you’re planning to visit, the museum is small but well done, the twins are friendly if you don’t make them the subject of every conversation, and the food in that part of Brazil is some of the best country cooking on the continent. We’d recommend the trip; we wouldn’t recommend it for the reason most people make it.
