The shot of Lesley Boulton narrowly avoiding a baton strike was a key image of the 1984-85 dispute.
But the negatives disappeared after she tried to bring an assault case.
They were considered a “crucial piece of evidence” but police argued the image may have been tampered with.
Without them, Lesley’s case – which backed up accounts by miners who said they were “indiscriminately battered” by police the same day – never went ahead.
No officer ever faced charges over the events at Orgreave, South Yorks, on June 18, 1984, during which 51 miners were injured.
Almost 30 years on, campaigners want justice and the Independent Police Complaints Commission (IPCC) is studying files from the time.
Lesley, 68, hopes they contain clues about what happened to the negatives, which she believes were stolen from a London picture library.
She also says her case files went missing after a “senior police officer from London” visited her Sheffield lawyers.
“Cops did not want my case to succeed — I was stitched up”
He turned up to talk about another case, before asking for documents to be copied.
Lesley was told he was left alone and the files were later found to be missing. She said: “I’m convinced I was stitched up.
“For obvious reasons the police didn’t want my case to succeed.”
On the day the picture was taken, 5,000 miners had gathered at Orgreave coking plant to protest.
Mum-of-two Lesley was there as part of the Women Against Pit Closures campaign group and was helping an injured miner.
Lesley says she was trying to attract a policeman’s attention when another mounted officer charged at her.
His baton missed her by inches – an incident photographer John Harris caught in two frames.
The fi lm was sent to London by train and John’s colleague Stefano Cagnoni worked into the early hours processing the negatives.
Lesley meanwhile contacted a law firm to complain.
Records show that South Yorkshire Police opened an investigation involving a chief superintendent.
A handwritten statement was taken from Lesley on June 27 that year and a typed one she still holds is dated the following month.
He also revealed where the negatives were stored.
The photo was shown off by an MP at the Labour Party conference that October and the London picture library Report/IFL soon began to reprint the image as interest took off.
But police claimed it might have been “foreshortened”, making it appear the officer was closer to Lesley. The negatives vanished soon after.
Sarah Blandy, Lesley’s solicitor in 1984 and now a law professor, told us they were “crucial” evidence and their disappearance “seemed very strange”.
On October 17, days after they vanished, an assistant director of public prosecutions wrote to Lesley saying the evidence did not justify a prosecution.
It was followed a week later by a letter from the deputy chief constable of South Yorkshire Police, claiming there was insufficient evidence.
Lesley, a member of Orgreave Truth and Justice Campaign, said: “What happened to me doesn’t compare with what happened to some miners.
But it must all come out.
“We need a public inquiry into what happened during the miners’ strike.”