A second British woman has died from "Brazilian butt lift" surgery, the BBC has learned, as fresh warnings come over the risks.
The British Association of Aesthetic Plastic Surgeons (Baaps) said it was the most dangerous cosmetic procedure to undergo.
The surgery has been made popular by celebrities.
But many people are putting themselves at risk by seeking cheaper procedures abroad, Baaps warned.
'One death in 3,000'
A Brazilian butt lift (BBL) is a cosmetic procedure in which fat is taken from one part of the body and then injected into the buttocks.
Baaps told the BBC's Victoria Derbyshire programme an estimated one in 3,000 die worldwide as a result of complications.
In August, 29-year-old Leah Cambridge died while undergoing a BBL procedure in Turkey.
A second British woman in her late 20s, also died this year, the Victoria Derbyshire programme has learned. An inquest into her death is due to happen within the next year.
Gerard Lambe, consultant plastic surgeon and Baaps member, explained: "It has the highest death rate of all procedures due to the risk of injecting fat into large veins in the buttocks, that can travel to the heart or brain."
'My bum was leaking'
One 23-year-old woman from Wales - who did not wish to be named - said she had been left scarred for life after having BBL surgery in February in Turkey.
Three months after the procedure, infected holes appeared on her buttocks.
"I couldn't walk properly for ages," she said.
"To be honest, when the holes came it was better as the fat was leaking out, which made it possible to walk again."
She said her buttocks were leaking for three months, "soaking all my clothes".
She added: "It smelled. I had to bandage it up every day.
"I honestly wish I could go back. I was happy with my body before. And now I paid a stupid amount of money to look like this."
Women who have undergone BBL surgery abroad have had to seek NHS treatment as a result of it going wrong, which Baaps estimates is costing the Health Service thousands of pounds.
It has calculated that serious complications - including pulmonary embolus, fat necrosis and abscess - that require time in hospital can cost more than £13,000 per patient.
Those affected require an average hospital stay of 20 days, it suggested, based on data at one hospital.
Cheryl Palmer-Hughes, a solicitor from Irwin Mitchell specialising in claims arising from cosmetic surgery abroad, said the number of girls inquiring about BBL complications is growing.
"Some patients have had skin grafts, [others] have had significant periods of time off work and some have suffered psychological issues," she said.
"Complaints also include having fat transferred to the wrong area of the body - for example, to the thighs rather than the buttocks."
'Still in pain'
A second woman who spoke to the BBC anonymously said she went to Turkey for BBL surgery two years ago because "the cost was a lot cheaper [than in the UK]".
She only met the surgeon for the first time 10 minutes before being put under general anaesthetic.
A few days later she had a really high fever, but when she tried to talk to the surgeon and nurses she says they stopped responding to her emails and texts.
She was admitted to hospital in the UK, and had to take a month off work.
Two years on, the woman said she still has pain from the surgery.
Ms Palmer-Hughes said more than half of her clients had undergone surgery in Turkey - with Hungary, Belgium and Spain also regular destinations.
She added that the women often signed documentation they do not get to read, with the terms and conditions containing a clause stating that any negative comments made online or on social media will result in a defamation lawsuit.
Watch the BBC's Victoria Derbyshire programme on weekdays between 09:00 and 11:00 BST on BBC Two and the BBC News Channel in the UK and on iPlayer afterwards.