Existence of documents has come to light after home secretary rejected investigation into events at South Yorkshire coking plant

The Home Office has revealed the existence of 30 secret files relating to the miners’ strike, a number of them relating to the “battle of Orgreave”. The disclosure has reopened the debate over what evidence home secretary Amber Rudd reviewed before rejecting an inquiry into the 1984 violence between police and miners.

Responding to questions from Yvette Cooper, chair of the home affairs select committee, Rudd confirmed the Home Office holds 30 non-disclosed paper files relating to the strike and brutal clashes between officers and miners at a coking plant in Orgreave, South Yorkshire.

Last month Rudd rejected the possibility of an inquiry into the violence at Orgreave, surprising and dismaying campaigners and thousands of former miners. Cooper had asked Rudd to clarify how she came to her decision, what paperwork had yet to be put into the public domain, and what documents the home secretary and Home Office officials had examined before reaching their decision.

Facebook Twitter Pinterest Barbara Jackson, from the Orgreave Truth and Justice Campaign, said she had no idea about the strike files. Photograph: Danny Lawson/PA

Barbara Jackson, secretary of the Orgreave Truth and Justice campaign, said: “We had no idea about these files; we thought they were all back with South Yorkshire police, had been sent to the National Archive or were with Margaret Thatcher’s papers.”

Cooper said: “We now know the Home Office holds 30 files relating to the strike and that [many] are relevant to events at Orgreave. But we still aren’t clear how many ... the home secretary looked at before taking her decision to rule out an inquiry and how many of the files will now be made public. We need answers to those questions.”

Cooper has asked for the subject heading of each file, along with queries over whether the home secretary or her officials requested or reviewed any files or evidence from the Independent Police Complaints Commission or South Yorkshire police before making the controversial decision.

“I have written to both the IPCC and South Yorkshire police – so that we can find out how much information still hasn’t been made public about what happened at Orgreave,” said Cooper.

Facebook Twitter Pinterest Home secretary Amber Rudd has been asked to reveal which strike documents she reviewed. Photograph: Will Oliver/EPA

She has also asked Rudd what documents from the Cabinet Office she examined relating to the 1984-85 miners’ strike, as well as Orgreave. One known document concerns the minutes of a 1984 meeting between Thatcher and home secretary Leon Brittan, where she appears to press him to speed up the prosecution of miners arrested at Orgreave.

After the clashes outside the plant, 95 miners were prosecuted for riot and unlawful assembly, offences that carry a potential life sentence. Their trial collapsed and all were acquitted amid allegations that officers colluded to write court statements.

Arbout 6,000 officers were called in to bolster police ranks protecting the Orgreave coking works, with a running battle between officers and miners, prompting questions over whether the police used excessive force.

The police operation was led by South Yorkshire – the same force “whose culture of malpractice with impunity” was exposed again five years later at the Hillsborough disaster, when 96 Liverpool football fans died.