Police could have prevented the murder of a disabled refugee by a vigilante who wrongly believed he was a paedophile, a damning report has said.
Bijan Ebrahimi, 44, was beaten to death and his body set on fire outside his home in Capgrave Crescent in Brislington, Bristol, by neighbour Lee James in July 2013.
Avon and Somerset Police repeatedly failed Mr Ebrahimi in the seven years before his death and showed "hallmarks" of racial bias, the Independent Police Complaints Commission (IPCC) found.
Officers ignored his pleas for help - including his final call about an hour before his murder - as he was viewed as a liar and a nuisance.
Police logs with potentially "racist undertones" included comments about the Iranian national's accent and him being "foreign", the report states.
They show "frequent negative views" and a lack of objectivity expressed by officers towards Mr Ebrahimi, known about by line managers and those in supervisory ranks.
Mr Ebrahimi's family said: "The IPCC's report speaks to the institutional racism that lies at the heart of Bijan's murder and immolation.
"Had the authorities not colluded in the race hate crime that Bijan suffered in his council flat over all those years, he would be alive today."
Their solicitor, Tony Murphy at Bhatt Murphy Solicitors, added: "Bijan was left defenceless against the race hatred of other tenants because the very institutions whose duty it was to protect him are infected with the same racism."
Mr Ebrahimi remained polite and persistent in reporting crimes against him, despite police failing to record them dozens of times.
The IPCC has published a report into Avon and Somerset Police's contact with Mr Ebrahimi in the seven years before his murder.
They show Mr Ebrahimi made 85 calls to the force between 2007 and July 2013, not including the weekend of his death.
In 73 of these, he reported incidents including racial abuse, criminal damage and threats to kill - but police failed to record these as crimes on at least 40 occasions.
The police watchdog found "consistent systematic failure" by call handlers, who breached standards on recording crimes, and identifying hate offences and repeat victims.
Jan Williams, an IPCC commissioner, said Mr Ebrahimi had been failed "on a number of levels, over a number of years".
"This failure was at its worst at the very time that his need was greatest. There could, and should, have been a very different response," she said.
Mr Ebrahimi identified himself as a victim of hate crime, but officers never recognised him as a repeat victim of abuse who needed help.
"Instead, his complaints about abusive neighbours were disbelieved and he was considered to be a liar, a nuisance and an attention seeker," she said.
"Neighbours' counter allegations were taken at face value and accepted, despite evidence to the contrary, and Bijan Ebrahimi found himself regarded as the perpetrator of the abuse, rather than as the victim.
"The constabulary's failure to challenge unfounded rumours that Bijan Ebrahimi was a paedophile was to form the backdrop to the fatal events of the July 14 2013.
"We found evidence that Bijan Ebrahimi had been treated consistently differently from his neighbours, to his detriment and without reasonable explanation.
"Some of the evidence has the hallmarks of what could be construed as racial bias, conscious or unconscious."
The IPCC has recommended that police officers and staff should be trained to recognise the potential for bias, while the force's leadership should send a "strong message" that discrimination is unacceptable.
Pc Kevin Duffy and PCSO Andrew Passmore were jailed at Bristol Crown Court last year after being convicted of misconduct in a public office.
They were dismissed from Avon and Somerset Police, along with Pcs Helen Harris and Leanne Winter.
The force also conducted misconduct proceedings against 17 officers and civilian staff, resulting in outcomes including two officers receiving final written warnings.
Reports show Mr Ebrahimi was wrongly branded a paedophile by neighbours after moving to a flat in The Whartons, Brislington, Bristol, in November 2006.
His home and car were set alight, he was racially abused and the word "pervert" was daubed across his front door.
One woman told police that a group of youths were planning to kill Mr Ebrahimi, while another said she believed an arson attack on his car was racially motivated.
A police officer wrote letters to residents insisting that Mr Ebrahimi was not a paedophile, and a fireproof letterbox and smoke alarms were fitted to his flat.
However, CCTV cameras were not installed and Mr Ebrahimi began filming his neighbours to gather evidence.
He was moved to nearby Capgrave Crescent in September 2007, with the false allegations that he was a paedophile following him.
In repeated calls, he reported feeling unsafe, racial abuse and threats to kill from his neighbours and that his panic alarm was not working.
It is reasonable to believe "that the perpetrators of the offences against Mr Ebrahimi, came to believe that they could act with impunity towards Mr Ebrahimi", the report states.
One police officer allegedly claimed Mr Ebrahimi caused problems with neighbours and was known for lying, making things up and "playing the race card".
In the hour before Mr Ebrahimi's murder, at 00.12am, he called police for help.
Winter told a call operator: "I'm absolutely not interested in speaking to him ever thanks ... I don't think anybody is to be honest, he's a pest."
In the report, lead IPCC investigator John Simick states that Mr Ebrahimi was "wrongly and unjustifiably" treated as a liar.
"Had his allegations in earlier years been recorded and investigated correctly, the truth of what he was enduring may have been discovered and, consequently, his murder may have been prevented," he adds.
"The failure to do so cannot be laid at the door of one officer or even the neighbourhood policing team.
"The extent of the failures and the degree to which they were apparent to others, including supervisors, are such that it might reasonably be said that the Avon and Somerset Constabulary, as an institution, must at least share the responsibility.
Andy Marsh, Chief Constable of Avon and Somerset Police, apologised for failing Mr Ebrahimi "in his hour of need".
"We've made many changes since Mr Ebrahimi's murder in response to the things we learnt and identified to be in need of change," Mr Marsh said.
"Taken together, these changes have transformed the way we operate and we will do all in our power to prevent a repeat of the circumstances surrounding Mr Ebrahimi's death."
Changes include spotting vulnerability early, understanding difference and closer working with partner organisations to complex problems.
"Embracing the principles of fairness, equality and diversity in our organisational culture has been and remains a significant priority, and these principles, together with our response to vulnerability are under constant scrutiny and tightly governed by me," Mr Marsh added.
He said some of the failings in Mr Ebrahimi's case were systematic but highlighted how actions of "a very small number of individuals had a catastrophic effect".