A damning report on the initial investigation into the deaths of serial killer Stephen Port's victims is expected to find multiple failures and missed opportunities.
Port drugged and raped four young men and dumped their bodies near his home in Barking, east London.
He was found guilty at the Old Bailey of their murders and was handed a whole life sentence in November 2016.
The victims' families have demanded to know why he was not stopped sooner and have jointly instructed specialist lawyers Hudgell Solicitors.
In a meeting with the Independent Office for Police Conduct they were told its report into the Metropolitan Police initial response will be damning and identify multiple failures and missed opportunities, according to their spokeswoman.
Relatives of Hull fashion student Anthony Walgate, 23, Kent chef Daniel Whitworth, 21, and Jack Taylor, 25, a forklift truck driver from Dagenham, met the police watchdog in London last week.
They were also told that the report would be sent to the Metropolitan Police by the end of May.
In total, the actions of 17 officers are under investigation.