It was only a couple of years ago that the phrase 'blood diamond' - those precious jewels which funded decades-long wars and killed people in their thousands - was on the tip of everyone's tongue.

Even those who missed Leonardo DiCaprio's 2006 film could not have failed to remember how Naomi Campbell was hauled to give evidence before judges in the Hague for receiving a few 'dirty looking' stones in 2010.

These stones, the court claimed, had come from Charles Taylor, the former Liberian dictator who funded the atrocities of Sierra Leone's 10 year civil war in return for the priceless jewels.

Campbell said she handed the diamonds to a colleague to give to charity, while Taylor was later found guilty of a host of crimes against humanity as a result of his involvement in the civil war, and sentenced to 50 years.

The diamonds are no longer mined to fund wars. But the scandal has not gone away. Now greed has created a new type of blood diamond in one African country, stained by the blood of those tortured and murdered.

Scroll down for video

Shocking: The diamond industry in Angola is behind a host of human rights violations - from torture to murder Pictured: Miners near the border with the Democratic Republic of Congo

Deadly: Journalist Rafael Marques found evidence of 500 cases of torture and 100 murders, which he put together in a book 'Blood Diamond: Corruption and torture in Angola', published in 2011

New meaning: But the reference was not to blood diamonds - explored in a 2006 film of the same name, starring Leonardo DiCaprio (pictured with co-star Djimon Hounsou) - but to the violence which still persists in parts of Angola's mining industry right up until today

Angola is a country which is familiar with the cost of blood diamonds: for more than six years in the 90s, the country's bloody civil was was propped up by billions made from selling the gems.

The war, which killed 500,000 over almost three decades, ended in 2002, and the country signed up to the Kimberly Process - which means all diamonds from Angola have to be certified 'conflict free'.

A report in 2011 reveals these diamonds are exported around the world - almost half to Dubai, with 19 per cent going to Switzerland and 22 per cent to Israel - but in previous years, almost all the diamonds were sold in London.

But there is nothing that guarantees they are violence free - and violence, in its most chilling forms, is how the private security guards and the soldiers, who are employed by companies and the government, keep control of the miners hoping to make their fortune sifting through the gravel in the river beds for the precious gems, according to campaigners.

The brutality used by the guards and soldiers shocks even the most hardened: it is not unusual for a beating, with machetes, cables and rifle butts, to end with a man bleeding to death.

Their crime? To not pay the bribes demanded by the guards or soldiers.

A video leaked late last year revealed the horror of such torture: a security guard is shown using the flat side of a machete to beat his victim's buttocks and the soles of his feet.

The guard tells him again and again he will die, while the 'prospector' - who is thought to have crossed the border from the Democratic Republic of Congo - begs for forgiveness as he tries to escape the merciless assault.

Beatings: Video released last year revealed the full horror of the beatings the miners can end up enduring

Brutality: It showed the minders being hit by private security guards with their machetes

Crime: It is thought the men had crossed the border from the Democratic Republic of Congo

Corruption: Marques revealed how the soldiers and guards use violence to control the people living in the diamond mining areas, while taking bribes from miners to turn a blind eye while they search for diamonds

Fear: In some cases, the beatings are so bad the victim dies from blood loss

'What's happening to people up there is horrible,' said Lara Pawson, author of In The Name of the People: Angola's Forgotten Masacre.

THE ANGOLAN MOTHER WHO LOST BOTH HER SONS TO THE DIAMOND INDUSTRY'S BRUTALITY Linda Moisés da Rosa has lost not one, but both of her sons to the violence of the diamond industry. Her younger boy was killed when the army collapsed the mine. But when she approached the police for help, she was chased away. It was not a case for them, they claimed. Her eldest son Kito decided not to return to the place where his younger brother died, instead heading for another area. But here, the private security guards were charging as much as $2,000 to let the miners 'wash the gravel' for diamonds. Kito didn't have the money, but kept working hoping he would be able to pay afterwards. But it wasn't to be: the guards caught up with him, striking him in the forehead first, before hitting him in the back of the neck. 'Then his life stopped,' said da Rosa afterwards, when Marques interviewed her. Linda wasn't even able to get his body back: it was washed away by the river when the guards dumped it. 'I lived with my sons, now I am alone,' she said. Their deaths - like so many others - were never investigated. Advertisement

'Even if they are not being beaten and killed, they cannot control the land and work the land for farming.

'They cannot even survive.'

For Angolan journalist Rafael Marques, the tipping point came when the army buried 45 miners alive back in September 2009.

Over the months that followed, he began to look into the atrocities being committed in the name of keeping profits safe in two areas, near the border with the Democratic Republic of Congo.

The report he subsequently published in 2011 detailed 100 and more than 500 cases of torture in just two areas.

In it, he dubbed them 'blood diamonds' - a moniker Pawson agrees with.

'To call them blood diamonds is absolutely fair enough,' she told MailOnline.

'People are still being exploited very, very badly, and some people are being killed, or abused physically, or even mentally.'

But getting anyone to speak was difficult: the community has learned to fear the guards and the soldiers.

When they did, what they had to say was horrifying, and often humiliating.

Others were beaten repeatedly with what ever the guards or soldiers could get hold of. One recounts ending up in hospital, unable to sit or stand for 12 days.

Others underwent far more unusual punishments: one group was forced to strip naked and fight each other for the entertainment of the guards, another to hold his hands as close to the fire as he could, while a third was forced to swim across a river which the guards knew would likely drown them.

High profile: Naomi Campbell was called to give evidence at the Hague after it was alleged she received a 'blood diamond' from former Liberian dictator Charles Taylor. She admitted to receiving the 'stones' - which she did not realise were blood diamonds - and then told her colleague to give them to charity

Living wage: But many miners feel they have no choice but to continue searching for diamonds

One man, named as Joseph, revealed: 'I was told to kneel over the stones and look directly to the sun for two hours.'

ANGOLA'S DIAMONDS: THE UK LINK For most of the last century, almost all Angola's diamonds were sold in London. Indeed, it was British companies which mined the diamond rich areas. And the influence of Britain and other colonialists can still be felt today. 'Britain had a major financial interest in Lunda,' said Lara Pawson. 'Nearly every single diamond went through London. 'And we were the people who began the indentured labour and physical punishment. 'We are partly responsible for what you see today.' Advertisement

James Almeida Manuel said his group was 'turned into stairs' by the soldiers.

'Each soldier began to step us with boots, from first to last. The whole squad ran over us,' he told Marques.

Once they were finished, he was sent to the village to get a bribe to free his friends - like so many others, forced to pay for their freedom.

But they were the ones who survived.

One person reveals how a miner was made to lie on his front and had a sandbag put on his back.

He was then hit until he bled to death.

But the killing was not confined to the miners: the year before, the bodies of a number of women were found by the wayside.

Their bodies had been burned and mutilated, the genitals removed.

Ridiculous: But despite bringing the human rights violations to the attention of the world, it is Marques who is facing a trial, and a possible nine years behind bars and more than £1million fine

ISABEL DOS SANTOS: AFRICA'S FIRST FEMALE BILLIONAIRE Isabel Dos Santos in Saint Tropez last July Isabel dos Santos is the daughter of President José Eduardo dos Santos - the man who has led Angola for the last 32 years, and who, in his 70s, shows little sign of lessening his grip on power. On paper, Isabel a very successful businesswoman: she owns shares in Angola's banking, cement, diamonds and telecom industries. Her most recent acquisition is said to be de Grisogono, a Swiss jewellers with an Instagram account full of the world's most beautiful people modelling their offerings. Model Bar Raefaeli, Gone Girl actress Emily Ratajkowski and Behati Prinsloo - who wore the company's necklace to the Oscars with husband Adam Levine - are just some of those who have worn their creations. And while she did not make her fortune through corruption, as such, there is said to be a huge level of nepotism to thank for a fortune which is said to amount to £2.3billion. A Forbes investigation - completed with the help of Marques - into Isabel's illustrious fortune revealed her father had played a little more than an encouraging role in amassing the wealth. Forbes suggests his daughter's wealth is almost an insurance policy: 'President Dos Santos it’s a foolproof way to extract money from his country, while keeping a putative arm’s-length distance away. 'If the 71-year-old president gets overthrown, he can reclaim the assets from his daughter. 'If he dies in power, she keeps the loot in the family.' When the article came out, Marques was arrested. 'I was surrounded by 45 special police officers,' Marques told MailOnline. 'Later, I learned the order had come direct from the ministry.' Advertisement

The police, Marques writes, know about the superstitions using body parts for 'magic rituals', to bring huge fortune to those in the diamond industry.

Marques has another theory: the murders were to sow 'fear and panic in the community'.

But they are in a desperate situation.

'Here there is nothing else to do [but search for diamonds]. We have to survive,' one miner told Marques.

'This time, I will take money to pay the army and not be tortured.'

Yet when Marques' 230-page book Blood Diamond was finally published in 2011, detailing all he had found, the government did not act.

Instead, Marques ended up fighting a battle against seven generals who own shares in the mines and private security companies.

The generals - including one of the president's closest allies - took exception to the book, and said they knew nothing of what they said were untrue claims.

'There is no link between the Angolan armed forces and the crimes exposed,' declared Joao Manuel, a lawyer for the generals, in March.

Pawson is sceptical about the statement.

'I think the generals are completely aware - these are people who know how the country functions. You cannot be a senior member of the biggest army in Africa and not know,' she said.

But the generals have pursued Marques through the courts nonetheless - first in Portugal for defamation, and then - after that was thrown out by a prosecutor, who said Marques' was 'clearly not to offend, but to inform' - in Angola.

This month, he will be dragged before a judge in a closed court, facing charges of criminal libel.

If found guilty, he faces a $1,600,000 (£1.07million) fine and as long as nine years in prison.

Terrified: There is no village mentioned on any of these pictures, taken in 2013, on the request of the subjects - perhaps showing the fear felt by many of the people working in Angola

It won't be the first time - Marques, who was in London picking up an award for his journalism from charity Index on Censorship just days before he was due in court in March, was jailed in 1999 for writing about Angolan president José Eduardo dos Santos.

But it hasn't deterred him.

Speaking to MailOnline, Marques said: 'I want my children to live in a different story - I will fight for it.

'But I don't fight with weapons, I fight with what I have - words.'

Meanwhile, the families who have lost their sons and daughters in the violence are left wondering what benefit a mining industry which makes foreigners rich and keeps vicious men powerful is to them.

Linda Moisés da Rosa, who has lost two sons to the brutality of the diamond industry, told Marques: 'The river of diamonds is here, in our land, where I gave birth to my son.

'My Kito drank water from the Rio Cuango. It was this water I gave him a bath.

'Foreigners are seizing diamonds. Our children cannot benefit from diamonds, and are killed.'