A homeless man with severe mental health issues was failed by three councils who neglected their legal duties to support him before he died, a safeguarding review has found.

The man, known only as Mr Yi, had his legal rights to be assessed for housing and social care support "repeatedly ignored" by Newham, Islington and Hackney councils, and his health and wellbeing deteriorated as a result of the "human rights breaches".

His death in 2018, after eventually being supported by Lambeth Council, was unconnected to the statutory failings but because he suffered serious harm a Safeguarding Adults Review (SAR) was commissioned.

The aim of the review, a joint effort between all four Safeguarding Adult Boards (SABs), was to stop other people experiencing chronic homelessness from being neglected. Its recommendations could shape new policy across London.

Mr Yi's case paints a bleak picture of cash-strapped agencies struggling to cope with a person's complex needs. He was bounced around between councils who did not want to accept responsibility for his care.

During discussions as part of the review, housing, social care, safeguarding and mental health workers, along with police, said they were "alarmed" but understood how each individual decision maker could have missed the wider implications of their actions.

They said frontline workers can become overwhelmed because of the large numbers of people with complex needs they encounter, and can become fatigued when their requests for multi-agency support are ignored.

They said Mr Yi's case was not unique, and that people can "ping-pong between services".

Mr Yi owned a home in Newham but abandoned it in 2006 and began sleeping rough. Two years later he was diagnosed with schizophrenia and seen by mental health professionals with little impact.

Between 2008 and 2012 he experienced "self-neglect". He stopped paying bills and began hoarding in his home. He was the victim of thefts and assaults while sleeping on the street, and was arrested himself numerous times.

The review found little evidence of sufficient support until 2012 when charity Shelter from the Storm gave him emergency accommodation and helped him apply to Newham Council, which found him sheltered housing.

But the support he received was fragmented and his housing benefit for sheltered accommodation was stopped because he owned a property.

In 2014 despite suffering two brain injuries that left him unable to live independently, no one considered the impact it would have on his ability to manage finances. The next year he was evicted from sheltered accommodation for racking up arrears.

Staff who brought the eviction proceedings "knew or ought to have known Yi was unlikely to have had capacity to litigate", yet he was given no support.

Mr Yi became street homeless again and was referred to Islington Council, whose No Recourse to Public Fund (NRPF) team housed him.

He was only given "partial support" with his finances because he couldn't keep appointments and because the council felt if it supported him it might mean it was liable for future care costs. It was involved in an ongoing dispute with Newham over who had duty of care for Mr Yi.

On his discharge from hospital following a subdural haemorrhage in 2016, Islington's NRPF team discovered he was in the UK legally and pulled support.

A housing application was then rejected by Newham Council because he owned a property. No consideration was given to whether he was able to live in his property, which the review found was a breach of the Homelessness Code of Guidance.

Eventually he was housed by Islington Council in Hackney, but "little regard" was given as to whether the accommodation was suitable. He was referred to Hackney's teams for specialist mental health support but another dispute arose as to which council should be supporting him.

No assessment was made of his capacity to apply for support and no one considered appointing an advocate for him.

In the end he was evicted from his hostel for not being independent and posing a risk to himself and others. No one at the hostel raised a safeguarding concern, which could have led to support.

The stand-off over whose concern Mr Yi was escalated in July 2017 when staff drove him first to Islington and then Hackney council offices for assessment, with neither agreeing to one.

After a spell in St Thomas' Hospital he was given an advocate by social workers from Lambeth Council. He was put in a nursing home and the council launched a safeguarding enquiry for "neglect and acts of omission".

During the review, partner agencies said adults experiencing chronic homelessness brought particular challenges in times of huge funding cuts.

The review found: "Practitioners did not act with deliberate intent to cause him harm. It is recognised Yi's conditions and resulting behaviours, coupled with the complexity of the legal framework, impact of austerity and lack of organisational support would undoubtedly impede their ability to carry out their functions.

"However, his legal rights to be appropriately assessed for support to meet his housing and social care needs were also repeatedly ignored and as a consequence his health and wellbeing deteriorated.

"It is accepted he suffered serious harm, such that the failings would likely have given rise to an action for a breach of his human rights. Given the definition of organisational abuse, the SABs and partner agencies involved may wish to reflect on what actions are required to ensure staff adhere to legal obligations and protect adults at risk experiencing, or at risk, of chronic homelessness."

The SABs recommended each authority's homeless strategy include appropriate assessments for people at risk of chronic homelessness and provides advocacy support.

They also want the London Safeguarding Adult Board to look at the reduction in costs preventative interventions have across health, housing, social care and criminal justice agencies and use the research to shape new policy.

A joint statement from the chairs of the SABs states: "Newham, City and Hackney and Islington SABs recognise Yi was let down by most of the organisations that were meant to help and support him.

"Councils across London and also nationally face similar challenges to address safeguarding issues related to homelessness.

"Improving how we support people who are homeless is a long term commitment that all four local authorities have prioritised.

The four boards have already begun work to reduce, as far as possible, the same things from happening again."