A powerful Greek family have accused the NHS of letting an heiress die on their watch after she was bitten by an insect, the Daily Mail can reveal.

Marissa Laimou, aged 30, was sadly discovered deceased in her bed by a housekeeper at the townhouse she shared with her parents in the affluent area of Knightsbridge, central London, on September 11.

In a tragic turn of events, Ms. Laimou – who was also known as Lemos – had recently conquered breast cancer and a very rare blood disease just months before her unexpected passing.

In the days leading up to her death, her family recalls her expressing significant health concerns at two reputable hospitals in London, including one where she was taken by ambulance, yet doctors ultimately decided to release her.

The affluent Lemos family, a major name in the Greek shipping sector, now intends to pursue legal action, confirmed a relative to the Mail, stating: ‘They will definitely hold them accountable. This is clearly negligence. Marissa’s life ended because of their actions.’

‘Keeping her for one more night could have made all the difference. They could have monitored her, administered antibiotics, and saved her life. She sought help from the right facility. Letting her go was a mistake.’

The relative, who has been in touch with Ms. Laimou’s mourning parents, added: ‘Marissa overcame cancer, and now this tragedy has unfolded. She lost her life in just a few hours. No parent should face the heartbreak of losing their child.’

The Mail can today reveal the full timeline of Ms Laimou’s death which has plunged her parents, twin brothers and wider family into mourning – including the harrowing texts she sent to a friend in hospital where she complained: ‘Nobody is checking up on me, nobody is coming.’

Marissa Laimou (pictured) – also known as Lemos – was found lifeless in her bed by her housekeeper on September 11

Pictured: Marissa with her twin brothers and mother and father before her tragic death

Ms Laimou, a theatre actress, had recently returned to London after a summer holiday with her family on the Greek resort island of Porto Cheli, where she was ‘perfectly alright’. 

She began feeling unwell on September 9, developing dizziness, itching, a high temperature and other signs of an infection, which proceeded to get worse in the night. 

The family say Ms Laimou called an ambulance and a doctor recorded a high fever of 39C 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 University College London Hospital (UCLH).

It was here that nurses, rather than doctors, carried out tests on her and concluded that she did not need to be kept in hospital. 

A family friend explained: ‘Marissa goes there and it was a nurse. They took the blood tests again, they gave her a drip with fluids. She was just waiting there. She went there at 2.30pm and at around 3pm they took the blood tests.

‘She was waiting, she sent some messages to her friend saying “Nobody is checking up on me, nobody is coming, I don’t know where they are, I’m still itching, I feel dizzy, I don’t feel well”.’

After her tests, Ms Laimou’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 in the morning of September 11. 

The family claim they have seen the official diagnosis given by doctors, which was a ‘toxic affect of venom’ caused by an ‘animal or insect bite’. 

In an emotional interview, the relative said: ‘It is negligence. No doctor examined Marissa. Only the nurses saw her and did the blood tests and passed the test to the doctor and the doctor said you can be discharged, that’s all.

‘Marissa’s mother, Bessy, believes her daughter has gone because of them. They should not have let her go, definitely. If it was not so urgent, her oncologist would not have sent her in an ambulance, they would have said go in an Uber or go later.

‘It was urgent. They didn’t address it with the serious way they should have done.’

Marissa is pictured with her mother Bessy and her father Diamantis, who is a part of the wealthy Lemos family

Ms Laimou (pictured) had staged a production of Romeo and Juliet in London and was preparing another theatre project

In an emotional tribute, the relative said: ‘Marissa was the most amazing girl with an amazing heart. 

‘Her passion, since she was a little girl, was musical theatre. She must have watched everything.

‘She was the most amazing girl and there are no words to describe her, a good, gentle, amazing heart, focused, ambitious, to do well.

‘She was in the US studying musical theatre. She came back to London, she worked at several art schools and a lot of theatre. Last February, she directed and produced and was the leading role of Romeo and Juliet.

‘She came back from Greece in the summer and started preparing another play, Oliver, and she found the cast and they had started some rehearsals every Friday.

‘Marissa passed away Thursday and she had scheduled to do more rehearsals on Friday.’

Although Ms Laimou’s wealthy family are from Athens, Greece, she was born and raised in the UK, growing up in a Knightsbridge townhouse with her two twin brothers, who are 26.

Her family were abroad at the time of her death and rushed straight to London when they were informed of the devastating news.

A relative said: ‘They are all shattered, we are a very close family. We cannot find why and how this could happen nowadays in 2025.

‘If she was in a village, you could understand it maybe. But she did it by the book. She did everything right.’

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.

Ms Laimou lived in Knightsbridge with her parents, while her uncle, George Lemos, and his family spent decades living in a block of luxury flats in Mayfair, where the average property is worth £4.5million.

Marissa is pictured with her two twin brothers who she grew up with in Knightsbridge. They are ‘shattered’ by her death

Marissa is pictured with her mother Bessy as a young girl. Her mother is heartbroken by her daughter’s death

Despite being born into astonishing wealth, Ms Laimou 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.

She had recently starred as Juliet in her production of Romeo and Juliet in London and was preparing for her latest Oliver performance.

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’.

A close relative told the Mail that Ms Laimou ‘loved London and couldn’t live anywhere else but England’.

Before her sudden death, Ms Laimou had battled through breast cancer. She was diagnosed in April 2023 and had to go through six months of ‘aggressive chemotherapy’.

But 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.

In an emotional tribute, a relative of Marissa’s described her as ‘the most amazing girl with an amazing heart’

She had incredibly overcome her health battles and was enjoying her life again before tragedy struck.

The family say they are still awaiting post-mortem results, having so far been left in the dark.

‘It keeps us in agony because we don’t know what happened to her,’ a relative said.

The Inner West London Coroner’s Court said: ‘The coroner is dealing with the sudden death of Marissa Lemos and investigations are ongoing.’

The Mail has contacted LOC and UCLH for comment.