The grieving family of a Greek heiress who was found dead hours after being discharged from an NHS hospital with a ‘toxic insect bite’ have demanded someone is held accountable a year after her death.
Marissa Lemos, 30, was tragically discovered in bed by a housekeeper at the townhouse she lived in with her shipping tycoon father and mother in upmarket Knightsbridge, central London, on September 11 last year.
Two days earlier, Marissa was bitten by an insect and later took herself to a private hospital on London’s Harley Street after developing symptoms of itching, dizziness, a high temperature and signs of an infection.
Marissa – who had recently overcome breast cancer – was rushed to A&E at University College London Hospital (UCLH) in an ambulance on September 10, 2025, due to the severity of her condition.
However, her family say that she was discharged without ever being seen by an NHS doctor – having only been assessed by trainee medics. In one of her last texts, she told a friend: ‘Nobody is checking up on me, nobody is coming.’
After being discharged, Marissa returned home at around 8pm, took her antibiotics and went to bed. The following afternoon, the family housekeeper found her dead in her bed.
The wealthy Lemos family – one of the biggest dynasties in the Greek shipping industry – have laid bare their year of torment to the Daily Mail, and are vowing to take legal action over the alleged clinical negligence.
Marissa’s mother, Bessy, and her shipping tycoon father, Diamantis, were told the initial diagnosis of her symptoms was ‘toxic effect of venom’ caused by an ‘animal or insect bite’.
Yet as they held an emotional memorial to mark a year since their daughter’s death in Athens last Friday, the family have still not been given an official cause of death or any answers as to why she was discharged when she was so visibly unwell.
Speaking exclusively to the Daily Mail, Ms Lemos said: ‘We are very frustrated. It is heartbreaking. We cannot believe we are in the UK in 2026 and no one can tell us how our daughter died when she was hospitalised a few hours before her death.
‘We will never have peace unless we find out the cause of her death and who is to blame for this catastrophic outcome.
‘We’ve been left in the dark and the system needs to be changed. My husband hopes that other people like Marissa can be saved. But I have lost my child. Can I bring her back? No – and we are still waiting.
Marissa Lemos, 30, was tragically found dead by a housekeeper at the family’s London townhouse on September 11 last year
Marissa is pictured with her mother Bessy and her father Diamantis. The wealthy Lemos family descend from a powerful line of Greek shipping magnates
Ms Lemos said that they have been battling for answers ‘since day one.’ It took nearly two weeks for a post-mortem to be carried out on Marissa.
This led to them having to delay the funeral and burial of their daughter in Athens.
But after a year of waiting for the post-mortem results, they were told that Marissa’s cause of death could not be determined.
The family say they have not been given a copy of the results despite repeated efforts through their lawyers.
They are also still awaiting toxicology testing that was supposedly completed on June 25 this year.
The Met Police have since told the family that there are microbiology tests that need to be carried out, which requires a specialist to interpret the results. The coroner will then determine if an inquest is required.
‘We have been very angry and furious since day one, since Marissa left the world,’ Ms Lemos said.
‘It is totally unacceptable and outrageous. We cannot believe this has happened.
‘They should have kept her that night. After all these tests, we are here today after a year and we still don’t know the cause of her death.
‘What would have happened if Marissa could have stayed on that night at the hospital? Obviously she would have been saved.’
The family marked Marissa’s one-year anniversary with a memorial service where she is buried in Athens last Friday.
‘We were looking at her grave thinking this is totally appalling and unbelievable what has happened to us,’ Ms Lemos said.
‘She did everything by the book. She didn’t stay helpless in her house and not asking for help. She went there in order for the people with the expertise to deal with it and they did nothing.
‘They just did some tests and let her go. A few hours later, she passed away.’
Marissa, a theatre actress, was born and raised in London, living with her parents at their townhouse in Knightsbridge.
She had recently returned to the capital after a summer holiday with her family on the Greek resort island of Porto Cheli, where she was ‘perfectly alright’.
But she began feeling unwell on September 9, 2025, developing dizziness, itching, a high temperature and other signs of infection, which proceeded to get worse in the night.
The family say Marissa called an ambulance and a doctor recorded a high fever of 39.1C but she decided to stay at home and said she would seek further medical attention if she did not feel well the next day.
But by the next morning, she had deteriorated so she took herself to the Leaders in Oncology Care (LOC), on London’s famous Harley Street, where she felt ‘very safe’ as she had previously been treated there for chemotherapy.
Medics carried out blood tests, gave her an antibiotics drip and antihistamine medicine. But due to the seriousness of her condition, they made the decision to call an ambulance to take her to UCLH.
It was here that trainees, rather than doctors, carried out blood tests on her and concluded that she did not need to be kept in hospital.
After her tests, Marissa’s family say she was discharged at 6.30pm and given antibiotics to take home with her, but she still felt seriously unwell and could not eat anything.
She would tragically go to sleep that night and never wake up again, with the family housekeeper finding her in her bed on September 11.
Marissa grew up in a Knightsbridge townhouse with her twin brothers, who are 26.
Pictured: Marissa with her twin brothers, mother Bessy and father Diamantis before her tragic death
Marissa is pictured with her mother Bessy as a young girl. Her mother is heartbroken by her daughter’s death
Marissa Lemos was a theatre actress and had starred in her own production of Romeo and Juliet
Her family were abroad at the time of her death and rushed straight to London when they were informed of the devastating news.
Her father, Diamantis, is part of the wealthy Lemos family who are one of the best known names in Greek shipping, with business roots stretching back to the early 20th century.
Despite being born into astonishing wealth, Marissa was keen to carve her own life, working in nurseries and as a receptionist at the Holiday Inn Bloomsbury while also juggling her real passion, theatre.
Although she was born and raised in the capital, she studied musical theatre in New York before going to the University of Arizona.
She had moved back to London in 2018 and credited her grandmother and friends ‘for always believing in her and pursuing her dreams’.
‘Marissa was a talented, beautiful young woman who had dreams and passions she had carried with her since she was a little girl,’ Ms Lemos said.
‘Above all, her greatest love was theatre.’
She had recently starred as Juliet in her production of Romeo and Juliet in London and was preparing to direct Oliver! with a cast she had chosen.
Before her sudden death, Marissa had battled through breast cancer. She was diagnosed in April 2023 and had to go through six months of ‘aggressive chemotherapy’.
After an operation, she was forced to spend four weeks in intensive care with hemophagocytic lymphohistiocytosis (HLH), an extremely rare condition where the body’s immune system does not work normally.
She had incredibly overcome her health battles and was enjoying her life again before tragedy struck.
Her devastated mother said: ‘After everything she had been through, including her battle with cancer and the difficult treatment that followed, Marissa did not give up on her dreams. Quite the opposite, she became determined to pursue them with even greater passion.
‘Marissa will always be remembered by those who knew and loved her for her extraordinary spirit, her kindness, her creativity and her determination to follow her passions.
‘She had a whole life ahead of her. She had so much more to give. And she should still be here.’
The Inner West London Coroner’s Court has been contacted for comment.
They previously said: ‘The case for Miss Lemos is still under investigation with the coroner’s office.’
A UCLH spokesman previously said: ‘We were extremely sad to hear of the death of Marissa Lemos. We offer our deep condolences to her family and friends at this sad and difficult time.’
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