South Yorkshire Police will not be investigated over its handling of violent clashes between miners and officers at Orgreave coking plant in 1984, the police watchdog has said.
The Independent Police Complaints Commission (IPCC) said due to the passage of time, allegations of assault and misconduct “could not be pursued”.
More than 120 officers and pickets were injured and 95 miners were charged.
The IPCC said its decision could be reviewed if further evidence emerged.
South Yorkshire Police referred itself to the IPCC after a BBC documentary in 2013 claimed officers may have colluded in writing court statements.
IPCC deputy chair Sarah Green said: “These are events from more than 30 years ago, and I have considered the impact such a passage of time could have on an IPCC investigation and possible outcomes.
“In addition, because the miners arrested at Orgreave were acquitted or no evidence offered, there are no miscarriages of justice due to alleged police failures for the IPCC to investigate.
“Allegations of offences amounting to minor assaults could not be prosecuted due to the passage of time; and as many of the police officers involved in events at Orgreave are retired, no disciplinary action could be pursued.
“I have therefore concluded that there should not be an IPCC-led investigation.”
The watchdog’s decision follows a two-year “scoping exercise” during which thousands of documents, film and photographs were analysed.
Ms Green said she accepted there were “concerns about some of the actions of individual officers” but said it was difficult to go back and apply current thinking and standards to the events at Orgreave.
“If this happened now, absolutely the IPCC would be investigating it,” she said.”But what we can’t do is wind back time to go back 30 years and redo what perhaps should have done then.”
Background: “The Battle of Orgreave”
By Dan Johnson
North of England correspondent, BBC News
What happened at Orgreave?
Monday 18 June 1984 was the most violent day of the year-long miners’ strike.
Thousands of pickets met huge lines of police – bussed in from all around the country – outside the Orgreave coke works on the edge of Sheffield.
The miners wanted to stop lorry loads of coke leaving for the steelworks. They thought that would help them win their strike, and help protect their pits and their jobs. The police were determined to hold them back.
There was violence from both sides.
The debate goes on about who acted first but police horses were sent to charge the crowd up the field and officers followed to make arrests. Many miners and police officers were injured.
Why was it significant?
The pictures of miners and police officers fighting shocked TV viewers. The numbers of police officers was unprecedented.
The use of police dogs, horses and riot gear in an industrial dispute was almost unheard of.
There were questions in court about the reliability of the police evidence. Many of the statements made by officers were virtually identical. At least one had a forged signature.
Eventually the case was thrown out and the miners were cleared.
What impact did it have on the community?
The miners felt they’d been set up.
They believed the intention that day was to beat them and make arrests, a show of force that would convince them they weren’t going to win. That left a bitter legacy of hatred and distrust of the police in many mining communities.
The police said they were just doing their job in the face of violence from striking miners. The strike lasted until March 1985.
Hundreds of mines closed afterwards, many miners faced redundancy. Even the Orgreave coke works itself has now gone. Houses and a business park are now gradually taking over the site.
This decision will disappoint the campaigners who say they want “justice”. But they say this is not the end. They will carry on campaigning for a full public inquiry into the way the police behaved throughout the year-long dispute.