Jagdip Randhawa, 19, from South West London, was punched by boxer Clifton Ty Mitchell during a night out in the city of Leeds on October 12.
After being hit, Jagdip Randhawa struck his head on a pavement and was taken to hospital.
He died five days later. Mitchell, now 26, was convicted of manslaughter and sentenced to seven years in prison for the crime in 2012.
The latest report into the killing has found that Mitchell had breached bail conditions for a previous violent offence 24 times in the preceding five months but no action was taken by Derbyshire Police.
"In my opinion, the procedure in place at the time of the incident was fundamentally flawed and was not fit for the control of persons deemed by the court system to require active monitoring," the report by the Independent Police Complaints Commission (IPCC) states.
"This process was in my opinion so flawed that none of the staff operating under it appeared to recognise the ongoing issues with this one individual and see the obvious opportunities missed," it notes.
An initial referral to the IPCC following a complaint by Jagdip Randhawa's family led to the force carrying out a local investigation.
In March 2015, the IPCC upheld an appeal by the family against that outcome and began its own probe.
"Our family will always be haunted by not knowing what might have happened if Mitchell had been arrested as he should have been," the victim's sister, Ms Majinder Randhawa, told BBC.
"It's important that the IPCC's report highlights the significant failings of Derbyshire Police - but it's devastating to know that Jagdip Randhawa's death was avoidable. We believe that Randhawa would still be here today, if Derbyshire Police had correctly managed Mitchell while he was on bail. It's impossible for us to ever get over that."
Derbyshire's Deputy Chief Constable, Gary Knighton said: "The IPCC report recognises that following the death of Mr Randhawa, we immediately reviewed the way that the force handled breaches of bail conditions where an individual is required to report to a police station.
"The force now has a more robust system in place to deal with a suspect who has failed to comply with their bail conditions. If someone breaches their bail, an officer is allocated to take action and deal with the breach."
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)