Peter Miller murder: 170 exhibits destroyed, returned or lost
The brother of a man murdered 31 years ago is to complain to a police force after it emerged 170 case exhibits had been destroyed, returned or lost.
Peter Miller, 24, was stabbed to death in Great Yarmouth on 9 December 1984.
His brother Tony said the absence of the evidence made any forensic breakthroughs unlikely and had "stolen" justice from the family.
Norfolk Police said it hoped people would still come forward to help the investigation.
Mr Miller was found stabbed on the kitchen floor of the family home in Camden Place, having last been seen by a neighbour in the afternoon.
His brother, a 54-year-old plumber from Gorleston, was originally arrested over the death but released soon afterwards.
Investigations then led to a number of other arrests, but no-one was ever charged.
Last year Norfolk Police admitted evidence had been destroyed or returned to original owners in 1991 - just seven years after the killing - but the number of items was not known.
However, letters seen by the BBC show 170 exhibits were cleared out, limiting any present day forensic review opportunities.
In the letters, police said officers had been "unable to ascertain who it was who took the decision to destroy the exhibits", but admitted it was "disappointing" it no longer had access to them.
The letters also show a can of CS spray recovered from the murder scene, classed as "clearly significant", was "unaccounted for".
Norfolk Police said the can was handed to the original senior investigating officer two months after the killing, but when recently asked what happened to it the force said he "simply cannot remember".
Mr Miller said he has suffered post-traumatic stress in the years following the death, and he has been "fobbed-off" by police on a number of occasions.
He believes there were many "missed opportunities" in the original probe, saying officers did not collect formal statements from his neighbours in the 1980s despite pledges they would.
"I'm going to continue fighting for Peter's justice because they [Norfolk Police] have stolen it," said Mr Miller.
"I want to show them that I will always be there, so deal with it now. I want them to stand up and say 'we're sorry, these are the mistakes we've made'.
"It's got to a point now where maybe an apology isn't enough - it's taken my life away. They're still trying to make excuses for the past."
Norfolk Police said it was still following a new line of enquiry that emerged in April 2013, adding that officers continued to support the family.
"As 31 years have passed since Peter Miller's death, we hope that people who may have not been prepared to come forward at the time may now feel able to provide information," a spokesman said.