“Dogs haven’t suffered like us,” says 30-year-old Fatima who stays alive by doing sex work when begging doesn't provide enough money to eat. Having fled to Istanbul from Syria's war-destroyed Aleppo six months ago, she is now safe from the bombing — but has been raped, racially abused and experienced more horrors than she ever imagined she'd have to deal with. As a Syrian beggar and (terribly paid) sex worker, she is treated as the lowest of the low in her place of refuge.

Fatima is just one of the people Stacey Dooley encounters in her new BBC3 documentary series, which looks at the various realms of sex work in Turkey. It's fascinating, shocking and extremely moving — perhaps one of Dooley's best films to date.

Amazingly, Turkey has state-run brothels which are guarded by lots of security and hidden away from public view. The women are able to work relatively safely, with the law on their side. But with the government covertly trying to eliminate prostitution, more sex workers are being forced to work unsafely in the streets.

Particularly in danger of being abused are trans women who work as prostitutes. Not recognised as female, they are not allowed to work in legal brothels so are particularly vulnerable, often getting attacked. Those trans women who still have male genitalia make a decent living because they are in demand with men who insist that they are "straight, family guys". Dooley spends time with a 40-year-old trans woman who explains that by sleeping with trans women, some of these men (she estimates that 70% are gay, 20% are fetishists) can convince themselves they're sleeping with a woman.

It's complicated stuff, and Dooley doesn't shy away from saying exactly what she thinks. As she ventures near a brothel, a group of young Turkish men ask her if she'll sleep with them. "Literally no chance," she says, visibly horrified. She's beautiful so she must want to have sex with them, they say, showing her photos of porn on their phones. When asked why they're going to trans brothels when they have wives, they insist that they're straight ("normal") but that trans prostitutes are more "hardcore." 

There's such a complex web of psychological, societal and cultural factors at work with these men, it's hard to know how to begin understanding it all. But what's clear is that religious doctrine and sexual repression are a very powerful combination. 

But perhaps most eye-opening of all — and an impressive feat of documentary-making — is Dooley's interview with two women who were kept by ISIS as sex slaves. Sold like meat at a market, they were forced to act out sexual fantasies for the leaders every day. After hearing their story, it all gets too much for Dooley.

This engrossing, important but deeply sad documentary will stay with you long after you've watched it. 

Sex in Strange Places is on iPlayer (BBC3) from 6pm on Tuesday 8th March