A mentally ill woman was discovered in a "mummified, almost skeletal state" after lying dead for more than three years in her flat, her family say.
Laura Winham, 38, was "abandoned and left to die" by the NHS and social services before her body was found by her brother in May 2021, they claim.
She is thought to have died in November 2017 after being referred to social care twice in the previous years.
Surrey council said it was a "truly tragic case".
The NHS has also been approached for comment.
Ms Winham, who had schizophrenia, lived in social housing in Woking, Surrey, and had become estranged from her family.
In 2014, a referral was made to Woking Community Mental Health Recovery and her GP, flagging that she appeared to have "untreated mental health issues", her family said. This was not followed up, they claimed.
After visiting Ms Winham in October 2017, in what was probably the last time anyone saw her alive, Surrey Police officers reported to Surrey County Council that she had been "self-neglecting, had little food, and appeared unaware of how to access local services for help".
Shortly after this visit, the markings on Ms Winham's calendar stopped. One of the last entries read: "I need help."
Her sister Nicky said the family were unable to maintain contact with her after years of schizophrenia caused her to believe they would harm her.
She said despite the "warning signs" about her deteriorating mental health, "everyone seems to have turned a blind eye".
She added: "Everybody who was in contact with Laura and had a duty to her at some stage simply wiped their hands of her and forgot her.
"She was abandoned and left to die.
"It's just heart-breaking to think of how she lived in her last few years, unable to ask for help, without anyone there for her."
Iftikhar Manzoor, of Hudgell Solicitors, who are acting for the family, said: "Laura was referred to adult social care teams twice, firstly in 2014 and then by the police in October 2017.
"Assessments of her needs were not carried out. Without doubt these were clear missed opportunities to intervene and carry out a welfare check."
Surrey Police said that after they received a concern for safety report at an address in Woking on 24 May 2021 they attended the property and found the body of a woman in her 30s.
Officers felt satisfied that there was no third-party involvement in the death following an investigation. A file was also passed to the coroner.
A force spokesperson added: "Officers previously attended the address in October 2017. No offences were identified and a report was completed and shared with adult social care at that time."
A spokesperson for Surrey County Council said it was a "truly tragic" and complex case, and that "every aspect" of it should be reviewed.
"We're committed to participating fully in the inquest process," they added.
They confirmed they would provide any information needed to support the coroner's inquiries.
Follow BBC South East on Facebook, on Twitter, and on Instagram. Send your story ideas to southeasttoday@bbc.co.uk.
Surrey County Council
Surrey Police
Farnham Repair Café celebrates saving visitors £150,000 through free product repairs
Alton charity shop Resurrection Furniture gives out a £1,000 grant
Controversial former Surrey County Council HQ development changed
Epsom Town Hall evacuated as bomb squad called
Police unit disbanded after Tyre Nichols' death
Unanswered questions from Memphis arrest videos
Zahawi sacked from UK government over tax row
The joy and the trauma of carrying a celebrity's baby
Unanswered questions from Tyre Nichols arrest videos
What happens when 'child geniuses' grow up?
'Elon Musk has made me embarrassed to drive my Tesla'
How Western tanks can change the Ukraine war
Reneé Rapp: From Sex Lives of College Girls to pop stardom
How learning this language rewires the brain
A makeover for iconic 200-year-old India building
Could a fungal pandemic turn us all into zombies?
A remedy for low motivation and passion
The 90s cop show that changed TV
How one volcano could make global chaos
© 2023 BBC. The BBC is not responsible for the content of external sites. Read about our approach to external linking.