families have come forward to share their own tales of horror

It is the mind-bending brew which has brought backpackers and gap year students flocking to the jungles of South America in ever greater numbers.

Ayahuasca, a hallucinogenic drink made from vines, has been used in shamanic cleansing rituals for centuries - but has recently become a major tourist draw in the rainforests where it grows, where lodges and retreats offer it as an 'authentic' Amazon experience.

But there is no need to cross an ocean: it can be found here in the UK - offered at retreats and is being taken at parties in idyllic rural towns by people seeking enlightenment.

Natural: The tea has been used for centuries by ancient Amazonian tribes in Brazil, Peru and Columbia whose shamans claim to use the psychedelic substance for healing and contacting the spirit world (file photo)

Tourist attraction: Drinking ayahuasca has become a key part of the backpacker trail for many making their way through South America, drawing people into the rain forest for an 'authentic' Amazon experience

Hidden danger: But what for many is just another gap year experience ends in tragedy for others. New Zealand backpacker Matthew Dawson-Clarke, 24, recently died during a ayahuasca retreat

People don't even need to leave the comfort of their own homes, with websites offering to deliver the 'herb' - legal in the UK and US, but not France or Canada - for less than £9 per 100g.

Frighteningly, the sellers say it would be 'unethical' to tell you how much is safe to take and how to prepare it.

Those looking for a weekend 'detox', including a tea ceremony can easily find them on offer across Europe.

It has even gained a celebrity following in recent years, with Sting and Lindsay Lohan gushing about its transformative qualities.

Yet it is not quite the harmless experience it may at first seem, beyond the violent vomiting it can induce at the start of every trip.

Earlier this month, New Zealander Matthew Dawson-Clarke, 24, who died during an ayahuasca ritual.

For those living with the plant brew on their doorsteps, there is an even darker and more terrifying side to the plant concoction - a side which is never mentioned in the tourist guides.

In Brazil, where consumption of the plant has led to numerous religious cults (one of which even boasts about giving it to newborns), the mind-altering tea has been linked with a string of suicides, murders and cases of mental illness and insanity - often at the very first time of ingesting it.

One mother, whose son allegedly became schizophrenic and committed suicide after taking the substance, said: 'This drug... has taken the lives of many other sons and daughters. It is responsible for the deaths of more people than anyone is willing to admit.'

Died: Bristol teenager Henry Miller's body was found last year after he took part in a ritual involving the tea. Despite this, people continue to attend the ceremonies, with it even becoming popular at parties in the UK

Religion: A healer begins a ayahuasca ceremony in Columbia, like the ones which attract the tourists. But locals are just as likely to be drawn in, especially by the religious cults which use it (file photo)

Warning: Many families have stories of tragedy to share, including that of Deise Faria Ferreira (right), who started drinking the tea with her congregation at a Santo Daime church earlier this year

Meanwhile, families of those caught up in the cults have told of their nightmares in trying to rescue loved ones from the grip of the brew.

The desperate daughter of a woman who recently disappeared during an ayahuasca 'purging ritual' told MailOnline that foreigners who think the drug will give them a cheap thrill should think again 'if they have any love for their own lives'.

She pleaded: 'It is a trip that you might not return from. Your curiosity could kill you, and cause suffering for your family. Please stay well away, you don't know the danger you are putting yourself in.'

Only the Amazonian Indians knew about ayahuasca until early in the last century. They used the vine, found throughout the jungles of Brazil, Peru and Colombia, for healing and contacting the spirit world.

Either my mother became ill and died, and [the cult] got scared and hid her body, or they used her as a sacrifice and murdered her. I don't know what they do in these rituals, I just know that she is no longer alive. Apoena Faria Ferreira

Shamans claimed they would use the drink to enable their 'spirit flight' - to visit their ancestors or descend to the underworld to locate the source of illnesses.

One of the first 'white men' to experience the drug was Brazilian rubber tapper Raimundo Irineu Serra, who founded the religious sect Santo Daime in the 1920s after claiming he saw the Virgin Mary - who appeared as the 'Queen of the Forest' in a vision.

The cult - which uses elements from Christianity and African religions - quickly spread from the northern state of Acre to the rest of Brazil and today is the biggest of the ayahuasca cults, which are believed to have as many as 30,000 members.

Countless other churches have sprung up since 2010, when Brazil's lawmakers allowed the use of ayahuasca for 'religious purposes'.

Fabio Pedalino, the leader of the Ceu do Gamarra church in south-east Brazil, which is part of the Santo Daime doctrine, told MailOnline it was 'impossible' that ayahuasca could take anyone's life.

He said he had never heard of anyone dying after taking the drink. adding: 'Newborns drink it, older people over 90 drink it. I've never seen or heard of any problems.'

Pedalino is 'completely against' the export of the plant brew - which they call Daime - to Europe for people to use for recreational purposes, without converting to their religion.

He said: 'This drink doesn't work without the doctrine. It's not worth having a Ferrari if you don't have a road to drive it down. Our doctrine is our road.'

Visions: The Santo Daime churches have embraced the traditional drink after the sect's founder Raimundo Irineu Serra first tried it in the 1920s, claiming it caused him to see the Virgin Mary as the 'Queen of the Forest'

Side effects: But for Deise - pictured here with fellow church members, dressed in a pink dress, centre front - the tea had different effects, becoming restless, unable to concentrate. She ended up on anti-depressants

Despite Pedalino's assurances, an increasing number of horror stories are beginning to emerge about the damaging and often deadly effects of the tea on followers - particularly those who already carried a hidden or underlying health problem or mental illness.

Many claim that the lack of proper controls, allowing anyone to open a 'church' and administer the drug, has led to an untold number of easily-avoidable tragedies.

The tea, which contains the psychedelic drug DMT, almost always induces profuse vomiting, discomfort and other physical effects before the start of the hallucinogenic experience - which is said to bring personal enlightenment by confronting the user with their darkest fears.

VOMITING THEN A TEN HOUR TRIP Ayahuasca, or yage, contains Dimethyltryptamine, known as DMT. Used in South America, especially in the Amazon basin, Ayahuasca is a drink produced from the stem bark of the vines Banisteriopsis caapi and B. inebrians. It is said to have healing properties and bring inner peace by purging toxins and can produce reactions including vomiting. Psychedelic experiences last six to 10 hours and are guided by experienced shamans in the South American countries where ayahuasca is legal to consume. Advertisement

In July, nursing assistant Deise Faria Ferreira, 41, who had been frequenting a nearby Daime temple for three months, left her home in Goiania, central Brazil, to take part in an ayahuasca cleansing ceremony. She has not been seen again.

Her devastated family believe she is the latest victim of the unregulated spread of the rituals in the country, and the protected use of the hallucinogenic tea under the guise of 'religion'.

Her daughter Apoena told MailOnline that Deise, who had never had any health problems, started showing signs of mental illness and high blood pressure two months after first starting to drink the tea in church ceremonies.

She said: 'She became very different, more restless, less able to concentrate. Her blood pressure kept going up, and none of the tablets she was prescribed was able to get it down.

'She ended up taking medicine for convulsions, depression and anxiety, as well as the blood pressure pills. She'd never had any problems with her health before. This was the effect of the ayahuasca, I'm sure of it.'

Under doctors orders, Deise spent a month off work and went to stay with a relative in the country's capital, Brasilia. But a day after returning home on July 9, she spent the day with the sect, whose leaders allegedly told her to stop taking the tablets.

Apoena said: 'They told her she was intoxicating herself with poison and that her body needed to be cleansed.

'She agreed to go to a nearby country retreat with six cult members to take part in a weekend-long ayahuasca purging ceremony.

Gone: Deise went to spend a month with a relative, and had recovered a bit. But then she returned in July and was encouraged to go to a weekend purging ceremony at a country retreat. She hasn't been seen since

Widespread: Since then her daughter has heard similar stories from people whose loved ones have either disappeared or been sent crazy by the tea, made from this root

'They told her not to tell anyone, not even her family, but she managed to call my grandmother and told her where she was going, and that she was going to be detoxified. That was the last time she spoke to her.

'When my grandmother called the cult leader the next day to find out where she was, he at first pretended he hadn't been with her.'

The details of what happened next are unclear. Those who were with Deise claim that after consuming ayahuasca on the Saturday night, she became agitated and asked to go home, but as one of them drove her out of the retreat she opened the car door and went off on foot.

The group claim they searched for her and could not find her - but did not explain why they failed to inform her family until Deise's mother's called - 23 hours after she went missing.

Police later found clothes belonging to Deise on the property covered in red stains, which tests later revealed was an unidentified substance other than blood.

She [her mother Deise] ended up taking medicine for convulsions, depression and anxiety, as well as the blood pressure pills. She'd never had any problems with her health before. This was the effect of the ayahuasca, I'm sure of it Apoena Ferreira

Luminol tests revealed blood splatters on walls in the interior of the building, although DNA tests to find out if it is Deise's have not yet returned.

Cameras on the only roads Deise would have walked along to leave the retreat failed to find images of her.

Two months on, Apoena said the family no longer holds out hope that her mother is alive.

She said: 'Either she became ill and died, and they got scared and hid her body, or they used her as a sacrifice and murdered her. I don't know what they do in these rituals, I just know that she is no longer alive.

'It's left the family in pieces. The authorities should better control the use of this drug before it destroys more lives.'

The case appears similar to that of American student Kyle Nolan, who disappeared in 2011 while at an ayahuasca lodge in Peru designed to help recruits 'open their minds to deeper realities'.

After initially joining his mother's pleas for help in finding her son, the shaman who ran the retreat admitted the 18-year-old had died after an ayahuasca session and that he buried his body at the edge of the property.

Apoena claims that since her mother disappeared, she has been contacted by other families who have suffered their own tragedies, which they too blame on the hallucinogenic brew.

She said: 'We've heard lots of cases of people who committed suicide immediately after taking the tea for the first time.

'Two families who live next to the Daime church my mother went to also spoke to us. One of them told us that their daughter killed herself after drinking the tea. Another woman, who lives right next to the temple, said her husband took his own life after taking the tea for the very first time.

'There are lots of cases of suicide, but the families are often poor and because it was suicide they don't have any way of proving that it was because of the drug, so the death goes unreported.

Devotees: Brazilian families are now speaking out to warn people against the drug, which actress Lindsay Lohan (pictured in 2014) credited with 'saving her life' after she drank the tea

Vision: Sting, pictured with his wife Trudie Styler, says the tea gave him the one religious experience of his life

'There are many other cases of people becoming schizophrenic after taking the tea, or going crazy for the rest of their lives. These churches are attracting more and more followers, most of them young people who go just for the hallucinations.

'Anyone can take the tea, there are no health checks and not even first-aiders on stand-by in case anything goes wrong.

'How many more people will have to die and how many more families will have to suffer before something is done about this?'

The claims are echoed by Claudetina de Almeida, 47, whose son Joao Raimundo, 20, killed himself by jumping off a viaduct after taking ayahuasca in a Santo Daime church where he had been a member for three years.

My son become delusional. He started saying he was the incarnation of Jesus Christ and that one of his sisters was the Virgin Mary. He once tried to attack me with a hoe. I thought he was possessed by an evil spirit. Claudetina de Almeida

Claudetina, a domestic maid, said her son began to show signs of schizophrenia a year after starting to attend the church, where the tea, considered a sacrament, is distributed to followers during services.

She said: 'He was a normal person who was happy and liked to joke. But the problems began after he started to frequent this religion.

'He started talking to himself, laugh for no reason and he seemed like he was on another planet. He become delusional. He started saying he was the incarnation of Jesus Christ and that one of his sisters was the Virgin Mary.

'He once tried to attack me with a hoe. I thought he was possessed by an evil spirit. It took me a while to realise the problem was his health. The psychologists said that he was schizophrenic.'

Joao reportedly drank poison before throwing himself off the viaduct in the centre of Sao Paulo, south-east Brazil. Following his death, Claudetina reported the case to police, but the investigation was closed two months later because of lack of proof linking ayahuasca to his death.

She said: 'I have no doubt that the ayahuasca developed schizophrenia in my son. And this drug took my son's life, as it has taken the lives of many other sons and daughters. It is responsible for the deaths of more people than anyone is willing to admit.'

Joao was a member of the Ceu de Maria church in Sao Paulo, the scene of another horror story linked to ayahuasca which shook Brazil in 2010.

The church's founder, and one of Brazil's best-known cartoonists, Glauco Villas Boas, 53, and his 25-year-old son Raoni, were gunned down by a masked assailant who had burst into their home.

The murderer, it turned out, was one of Glauco's followers, whose family claimed he had developed schizophrenia after starting to frequent the church and use the mind-altering drink.

Victim: Claudetina de Almeida believes the tea (pictured) caused her son's schizophrenia, which eventually led to his death

Easy: People in the UK don't need to travel to the Amazon to try it for themselves, but order it online (pictured)

Difficult: But the website, which is based in the Netherlands, refuses to explain how to brew the tea - saying they believe it to be 'impossible and unethical' to advise people through the internet

When police caught 24-year-old Carlos Eduardo Sundfeld Nunes he claimed he had wanted to kidnap the cartoonist to prove to his family that his younger brother was, in fact, Jesus Christ.

His father, Carlos Grecchi Nunes, later told Brazilian magazine Isto E: 'He started talking about religion the whole time. He once spent five days without sleeping, reading the Bible. He said he was the reincarnation of Jesus Christ.

'One day he arrived back from the church so out of his mind that his brother had to tie him to the gate. His mother asked the church to stop giving him the tea, but it was in vain.

'On New Year's Eve he went to church and, on his way back, was so high that he crashed his car in a ditch.'

Meanwhile, on numerous online discussion forums the families of other members of Brazilian ayahuasca sects share stories of their loved ones own descent into isolation, and their desperate attempts to take them out.

In one, Suele writes: 'I've been trying to take my daughter out of Santo Daime for five years. She lives only for this sect, she's forgotten her brothers and other family. She even lost custody of her 10-year-old daughter, and still she doesn't leave.

'God is liberty and not imprisonment. This sect is brainwashing and addiction.'

Another mother, Rosangela, writes: 'I know a lot of young people who developed mental problems after they started taking this tea, and there is a high rate of suicide among those who go there. This sect brainwashes people, they brainwashed my son. Please the authorities need to do something.'

I've been trying to take my daughter out of Santo Daime for five years. She lives only for this sect, she's forgotten her brothers and other family. She even lost custody of her 10-year-old daughter, and still she doesn't leave Suele, parent on online forum

But Brazilian 'church leader', Fabio Pedalino, has defended ayahuasca's reputation and claims it helps cure people mental illness and insanity - but only if administered by people who are trained to do so.

He said: 'We have seen many mad people cured through Daime. But we've seen that, with people with schizophrenia, it only works if they drink a very small amount.

'A large amount makes the voices in their head speak even louder, which can make their illness worse.

'In the same way, you have to be careful if people are taking other types of medicines, because this can also cause complications if mixed with Daime.'

'The problem is when you get people who are only interested in money, who prepare it wrongly and mix it with other substances.'

The dire warnings about ayahuasca don't seem to have reached the increasing number of celebrities, including Jim Carrey, Tori Amos and Courtney Love, who claim to have had their lives changed after their own ayahuasca experiences.

Lindsey Lohan claimed the herbal tea 'saved her life', saying she saw her own birth and death during the intense hallucination, and that the experience helped her let go of the 'wreckage of the past'.

And Sting, who says he drank ayahuasca in a Rio de Janeiro church, said the hallucinogenic concoction was 'the only genuine, religious experience I've ever had'.

He remembered how after drinking the brew he felt 'something coursing through my body, like an intelligence searching everything. I am wired to the entire cosmos. I look at the ground and I see a crack in the ground and inside that crack I see a little flower growing… it's my brother.'

The rush to follow in the stars' footsteps has created a tourism boom around the Amazon basin, where resorts and lodges offer 'cleansing ceremonies' for ayahuasca pilgrims, conducted by shamans, for up to £500 a time.

The owner of one jungle lodge resort, in the Colombian town of Leticia, on the border with Brazil, told MailOnline that many people come intent on drinking the tripping tea, but most of the partakers are 'thrill seekers just looking for that out-of-body experience'.

Laws: Yage became legal to consume in Brazil in 2010, as long as it was for 'religious purposes'

Psychiatrist Ronaldo Laranjeira, from Sao Paulo Federal University, believes that ayahuasca is so dangerous it should be banned, even at the expense of religious liberty.

He said: 'This is a drug with hallucinogenic effects, which profoundly alters the chemicals of the brain of whoever consumes it. But even children, according to the law, can take it.

'The tea should not be recommended for any use, not even in religious ceremonies, like those of Santo Daime. From a scientific point of view, it doesn't make the slightest sense.'

Many make the point that, if the use of the ritual in church congregations is dangerously unregulated, how much more so the shamans selling psychedelic experiences to young backpackers deep in the jungle.

As well as the deaths of a number of Western tourists, there have been reports of other abuses at the hands of shamans, including rape, sexual molestation and robbery.

He was screaming louder than I've ever heard a human scream. Something must have happened to him to cause him to realise that he just did something that was very wrong for his body. Witness to the death of New Zealand backpacker Matthew Dawson-Clarke

In 2010, a 23-year-old German woman was raped and brutally beaten by a shaman and his accomplice during an ayahuasca ceremony in an Amazonian village.

And in 2013, a Slovakian woman filed charges against a shaman, claiming she had been raped during a ceremony in Peru.

Similarly, there are rarely checks on thrill-seekers' medical history, a fact that has resulted in the deaths of a number of young tourists.

Last year British teenager Henry Miller died after taking ayahuasca in a shamanic ceremony in Colombia - just days after Lindsey Lohan credited the brew with saving her life.

The latest victim, Matthew Dawson-Clarke, suffered a cardiac arrest after consuming another, tobacco-based tea in preparation for an ayahuasca cleansing ceremony during a spiritual retreat in Iquitos, in the Peruvian Amazon.

One witness said: 'He was screaming louder than I've ever heard a human scream. Something must have happened to him to cause him to realise that he just did something that was very wrong for his body.'

But the Santo Daime leaders claim that, on the contrary, the 'sacred' tea can actually cure insanity.

Responding to a query on their website about whether ayahuasca can 'make you crazy', the church replied: 'There have been cases of insane people who have come to Santo Daime and been cured. Other crazy people have remained crazy.

'However, in respect to becoming crazy because of taking Daime, I've never witnessed or heard of any case. The Santo Daime has cured many things, but when it is God's sentence, there's no other way.'