Sextortion is the fastest-growing scam affecting teenagers globally and has been linked to more than 27 suicides in the US alone. Many of the scammers appear to be from Nigeria - where authorities are defending their actions and are under pressure to do more.

It has been two years since Jenn Buta’s son Jordan killed himself after being targeted by scammers who lured him into sending them explicit images of himself, and then tried to blackmail him.

She still can’t bring herself to change anything about his bedroom.

The 17-year-old’s basketball jerseys, clothes, posters and bedsheets are just how he left them.

The curtains are closed, and the door is shut to keep memories of him that only a parent would understand.

“It still smells like him. That’s one of the reasons I still have the door closed. I can still smell that sweat, dirt, cologne mix in this room. I'm just not ready to part with his stuff,” she said.

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Jordan was contacted by sextortion scammers on Instagram.

They pretended to be a pretty girl his age and flirted with him, sending sexual pictures to coax him into sharing explicit photos of himself.

They then blackmailed him for hundreds of pounds to stop them sharing the pictures online to his friends.

Jordan sent as much money as he could and warned the sextortionists he would kill himself if they spread the images. The criminals replied: “Good… Do that fast - or I'll make you do it.”

It was less than six hours from the time Jordan started communicating until the time he ultimately took his life.

“There's actually a script online,” Jenn told BBC News, from her home in Michigan, in the north of the US. "And these people are just going through the script and putting that pressure on.

"And they're doing it quick, because then they can move on to the next person, because it's about volume.”

The criminals were tracked to Nigeria, arrested, and then extradited to the US.

Two brothers from Lagos - Samuel Ogoshi, 22, and Samson Ogoshi, 20 - are awaiting sentencing after pleading guilty to child sexploitation charges. Another Nigerian man linked to Jordan’s death and other cases is fighting extradition.

Jordan’s tragic story has become a touch point in the fight against the growing problem of sextortion.

Jenn is a now high-profile campaigner on TikTok – using the account Jordan set up for her – to raise awareness about the dangers of sextortion to young people. Her videos have been liked more than a million times.

It’s feared that sextortion is under-reported due to its sensitive nature. But US crime figures show cases more than doubled last year, rising to 26,700, with at least 27 boys having killed themselves in the past two years.

Researchers and law enforcement agencies point to West Africa, and particularly Nigeria, as a hotspot for where attackers are based.

In April, two Nigerian men were arrested after a schoolboy from Australia killed himself. Two other men are on trial in Lagos, after the suicides of a 15-year-old boy in the US and a 14-year-old in Canada.

In January, US cyber-company Network Contagion Research Institute (NCRI) highlighted a web of Nigerian TikTok, YouTube and Scribd accounts sharing tips and scripts for sextortion. Many of the discussions and videos are in Nigerian Pidgin dialect.

It’s not the first time that Nigeria’s young tech-savvy population has embraced a new wave of cyber-crime.

The term Yahoo Boys is used to describe a portion of the population that use cyber-crime to earn a living. It comes from the early 2000s wave of Nigerian Prince scam emails which spread through the Yahoo email service.

Dr Tombari Sibe, from Digital Footprints Nigeria, says cyber-fraud such as sextortion has become normalised to young people in the country: “There's also the big problem of unemployment and of poverty.

"All these young ones who don't really have much - it's become almost like a mainstream activity where they don't really think too much about the consequences. They just see their colleagues making money.”

African human rights charity Devatop has said the current methods of handling sextortion in Nigeria have failed to effectively curb the practice. And a report from NCRI said that celebrating sextortion crimes are an established part of the internet subculture in the country.

In an exclusive interview with the BBC, the director of Nigeria’s National Cyber Crime Centre (NCCC) defended his police force’s actions, and insisted it was working hard to catch criminals and deter others from carrying out attacks.

Uche Ifeanyi Henry said his officers were “hitting criminals hard” and said it is “laughable” that anyone should accuse Nigeria of not taking sextortion crime seriously.

“We are giving criminals a very serious hit. A lot have been prosecuted and a lot have been arrested,” he said. "Many of these criminals are moving to neighbouring countries now because of our activity.”

The NCCC director pointed to the fact that the government has spent millions of pounds on a state-of-the-art cyber-crime centre, to show it was taking cyber-crime seriously, especially sextortion.

He said Nigerian teenagers are also being targeted, and he argued that the criminals were not just a Nigerian problem, with other sextortionists in south-east Asia. Tackling them would require global support, he said.

With that in mind, the director and his technical team are this week visiting the UK’s National Crime Agency, which last month issued a warning to children and schools about a rise in sextortion cases.

The visit is designed to improve collaboration on sextortion and other cyber-crime investigations. It follows similar recent meetings with Japanese police.

Meanwhile, Jenn Buta continues to campaign alongside Jordan’s father John DeMay. They regularly give advice to young people who may become victims.

Advice that Jenn and many law enforcement agencies regularly give people targeted by sextortionists includes:

• Remember you are not alone and this is not your fault
• Report the predator’s account, via the platform’s safety feature
• Block the predator from contacting you
• Save the profile or messages - they can help law enforcement identify and stop the predator
• Ask for help from a trusted adult or law enforcement before sending money or more images
• Co-operating with the predator rarely stops the blackmail and harassment - but law enforcement can