A British student was left reeling after watching a 'nervous' teenage girl take part in her first adult film with 20 masked strangers.

Anna Adams, 23, visited a pornography set in Madrid as part of an investigation into the booming industry, and was shocked and upset by the 'exploitative' nature of the filming process.

Along with Ryan Scarborough, 28 and Cameron Dale, 21, Anna visited the studio of Ignacio 'Torbe' Allende Fernández, nicknamed 'the King of Spanish Porn', who has produced over 1,000 adult movies and whose website boasts 250,000 visits a day.

Appearing on new BBC Three series Porn Laid Bare, feminist student Anna raised concerns over the safety of the 19-year-old Russian woman who was taking part in her 'first gang bang' just one week into the job.

In his studio, Torbe shoots two or three graphic sex scenes, known as bukkakes, per week, during which young girls are expected to perform sex acts on up to 100 men over the course of several 'sessions'.

Anna grew concerned for the safety of a 19-year-old Russian woman (pictured) who is taking part in her 'first gang bang' just one week into the job and did not share her name

A masked man undressing ahead of a bukkake, during which young girls are expected to perform oral sex on up to 100 men over several 'sessions', in a studio in Madrid

One session alone will earn the actress €3,000 (£2,560), amounting to €9,000 (£7,684) per week, while the men are often unpaid volunteers taking part 'just for fun'.

'They get very nervous in the beginning,' Torbe says of the young actresses, 'because they see a lot of guys' - but he insists the women can stop at any time they want.

The notorious producer says he takes an 'old school' approach to the porn industry, and sees it as his job to educate the '95 per cent' of actresses he encounters who are young and inexperienced.

While the women are paid actresses, the men approach Torbe themselves and some have been taking part in bukkakes for up to 15 years.

Torbe invites the trio to watch him filming the 'gang bang' featuring the Russian teen and ten men, most of whom are masked.

Unidentified men strip off before filming begins. Anna is shaken by what she sees, telling cameras: 'The impression that I'm getting is that this is kind of quite exploitative'

Men are masked and sometimes unpaid. While the women are paid actresses, the men approach producers themselves and some have been taking part in bukkakes for up to 15 years

The Spanish producer, who describes the sex act as 'making love', says of the masked men: 'We work with people who don't want to be famous. They just [do] this for fun. They don't want [their] family to recognise them.'

Despite her initial nerves, the young Russian woman eventually enters the studio and stands in the middle while three men take it in turns to perform sex acts on her.

But Anna is shaken by what she sees, telling cameras: 'It's a really really seedy place. The impression that I'm getting is that this is kind of quite exploitative. It's not really porn, it seems to be men coming here to have sex with a woman who gets paid.'

Her co-star Ryan adds: 'It's upset me, because I watch a lot of porn, to come to a place like this and to see how seedy and how dirty this place is. It's just freaked me out.'

Anna expresses her concerns to the young actress. It comes after a survey suggested almost a quarter (23 per cent) of people aged 18-25 who watch porn think they might be addicted

Inside his office, student Anna (left) Anna tells producer Torbe her concerns that the young woman seems 'a bit scared' - but he laughs it off, insisting the woman is 'enjoying' filming

Film crews visited the studio of Torbe (pictured), nicknamed 'the King of Spanish Porn', who has produced over 1,000 adult movies and whose website boasts 250,000 visits a day

Afterwards, Anna shares her concerns that the young woman seems 'a bit scared' - but producer Torbe laughs it off, insisting the teen is 'enjoying' filming the sex scene and is free to leave the set at any time.

Speaking to the actress, Anna says: 'You say you're OK, but I'm just worried.

'As a young woman I'm worried that when we leave, you're here, and you're the only woman and there's all these men and I'm just worried about you.'

The three-part series follows six young Brits with different attitudes to pornography as they undertake a journey to explore the ethics of porn in Spain’s booming sex industry.

Anna Adams, 23, visited a pornography set in Madrid as part of an investigation into the booming industry, and was shocked and upset by what she saw.

Frequent porn user Ryan (pictured) was also upset by what he saw, saying: 'It's upset me, because I watch a lot of porn, to come to a place like this and to see how seedy and how dirty this place is. It's just freaked me out'

BBC Three's Porn Laid Bare is three-part series following six young Brits as they undertake a journey to explore the ethics of porn in Spain’s sex industry. In episode one, Anna (third left), Ryan (third right) and Cameron (far right) visited Torbe's notorious studio in Madrid

Spending three weeks on a variety of pornographic sets across a spectrum of genres, the group explore how porn has shaped their own views of sex, whilst asking tough questions about porn that many believe demeans women and minorities as well as promoting violence and unsafe behaviour.

It comes after a new survey suggested that almost a quarter (23 per cent) of people aged 18-25 who watch porn think they might be addicted.

The survey of over 1000 people, carried out online by Deltapoll for the BBC Three documentary, showed that over three quarters of young men (77 per cent) and nearly half of young women (47 per cent) admitted to watching pornography within the last month alone.

Porn Laid Bare is available on BBC Three from Thursday 14th March