Police chiefs were told to watch Arthur Scargill with a view to prosecution during the miners' strike 25 years ago, according to papers seen by the BBC.
The strike was a watershed moment in British industrial history that led to the near destruction of one of Yorkshire's biggest industries.
A document from the time shows that in South Yorkshire a chief superintendent had been detailed to watch Mr Scargill.
Humberside's then Chief Constable David Hall denied any political control.
Early in 1984 the National Coal Board announced 20 pits would close and 20,000 jobs would go.
Miners walked out in protest across the country and on 12 March National Union of Miners (NUM) President Arthur Scargill announced a national strike.
Local police forces found themselves overwhelmed by the demands of the picket lines.
Thousands of officers were drafted in as reinforcements from all over the country.
The then Chief Constable of the Humberside force, David Hall, found himself in charge of coordinating the national operation to police the strike.
At the time there were suggestions that Downing Street was behind much of the police activity, but Mr Hall has denied this.
He said in 1984: "Many suggestions have been made and they're entirely without foundation.
"The police force of this country is in no way politically controlled. If the day comes that it is, it would be a sorry day for this country."
But, under the Freedom of Information Act, the BBC has obtained internal Home Office documents from 1984 which relate to the miners' strike.
One of them refers to police efforts to prosecute union leader Arthur Scargill.
And though it concludes there is insufficient evidence to charge Mr Scargill with any offence, it reveals the then, and now late, Chief Constable of South Yorkshire Peter Wright had "detailed a chief superintendent to keep an eye on Mr Scargill's activities in order continually to assess the available information with a view to possible prosecution".
Twenty five years on the BBC showed this information to David Hall who is mentioned in the memo as being aware of the "sensitivity of it".
The document refers to plans for future discussions between Mr Hall and fellow chief constables.
Mr Hall said, "I can assure you there was no conspiracy on the part of the police service to as you might say to 'nail Scargill'.
"That's not the case. It was just a normal procedure to keep an eye on somebody who they thought might have been the cause of the disorder."
Dave Douglass was a staunch NUM official.
His anger and sense of injustice have not dimmed with the passage of time.
He said: "Well, I think it makes you very angry because they weren't trying to prosecute Arthur Scargill for something he had done, but trying to find something to prosecute him for.
"They were fishing about looking for something so they could take him out of the picture."