A police officer jailed for taking sickening pictures of murdered sisters Bibaa Henry and Nicole Smallman told friends he covered up an attack on a group of Asian men, a watchdog investigation found.
Disgraced Pc Deniz Jaffer bragged in a WhatsApp group about a police cover-up involving three "white fellas" arrested for assault at a football protest.
He said they were released after chatting with them "off the record", claiming it would be at the victims' request - despite not contacting the injured party.
He also twice used an offensive racial term to refer to the Asian men, days after he and colleague Jamie Lewis took disrespectful photographs while protecting a murder probe crime scene in Fryent Park, north London, in June 2020.
A report by the Independent Office for Police Conduct (IOPC), published for the first time on Friday, said Jaffer's conduct over the supposed cover-up "indicates a corrupt attitude within policing that specifically targets people from the South Asian community".
Jaffer later tried to dismiss the messages as "chit chat" and an attempt to be "funny".
A Metropolitan Police investigation concluded Jaffer's account was made up, and that the assault on the Asian men did not happen.
The IOPC report found: "The sentiment expressed by Pc Jaffer is likely to bring discredit on the police service and undermine public confidence in policing, especially but not limited to, members of the South Asian community.
"Concerning is Pc Jaffer's reference to this as 'chit chat' and 'gossip'."
Jaffer later told investigators he was not racist, and had merely repeated the racial slur a friend had previously used.
The incident was unconnected to the Fryent Country Park murders, but was uncovered during a forensic examination of his phone following the investigation into his behaviour at the crime scene.
The IOPC report also revealed that Jaffer's colleague Lewis initially told police he was "95% certain" he had not taken photographs of himself next to the bloodied bodies of Ms Smallman and Ms Henry.
It was later discovered that he had taken at least two photographs, while Jaffer took four pictures of the bodies in situ.
Both men were jailed in December 2021 for two years and nine months after admitting misconduct in a public office.
Sentencing judge Mark Lucraft said they demonstrated "appalling and inexplicable conduct", while the Metropolitan Police apologised to the victims' family for the defendants' "shameful" and "utterly unprofessional" actions.
Danyal Hussein, 19, was jailed for life with a minimum term of 35 years for the murders.
Three serving Met Police officers faced misconduct meetings last month for failing to challenge or report the inappropriate photographs when they were either shared with, or shown, to them. They were given written warnings.
Scotland Yard said it had implemented the recommendations made by the IOPC regarding officers' behaviour, adding the force "made significant changes to improve our standards and culture since this happened".
