Transport Minister Kim Howells has revealed that as a National Union of Miners (NUM) official, he destroyed union records during the miners' strike of 1984-85.
Kim Howells burned NUM records during strike in a 'panic'
On BBC Wales' Good Morning Wales programme on Monday, Mr Howells admitted that his actions had followed the death of taxi driver David Wilkie, killed when two striking miners dropped a concrete pillar from a road bridge on to his car.
Mr Wilkie had been taking two working miners under police escort to a Mid Glamorgan pit.
Although his death was unrelated to any union work, Mr Howells felt the police would use the incident as an excuse to raid the NUM offices and get hold of their plans for running the strike.
The incident aroused much public horror and is told in " The Miners' Strike" which will be shown on Tuesday 2100-2230 GMT, on BBC TWO.
Mr Howells explained that he had been tipped off about the tragedy by a reporter.
He spoke of his "sense of revulsion" as the death of the man and added: "I felt physically sick that someone had died as the result of the action of one of our members."
He said he then rushed to destroy records at the NUM Pontypridd HQ which would have only revealed NUM's strategy when planning their legal right to picket.
In the interview, he stressed that he felt a police raid on the offices could have compromised the strategy and that was the sole motive for his actions.
"I panicked" he said, "and destroyed a lot of historic documents."
The minister said that in November 1984 the strike had been going on for a long time and passions were running high among NUM members about miners who were abandoning the strike and returning to work.
Howells feared police would raid NUM officers seize their strike plans
Two men were convicted of the murder of Mr Wilkie, a charge later reduced to manslaughter. They were released in 1989.
The BBC Two documentary looks at five young men from an ordinary Yorkshire mining village who were thrown into this extraordinary conflict.
It reveals the emotion, deep hatred and sheer adrenaline which engulfed them as they became embroiled in the great miners' strike.
Twenty years on, The Miners' Strike talks to these five flying pickets about their year of living dangerously and finds out what the future was to hold for each of them.
The programme also meets the police officers, working miners, families and politicians who crossed their paths.
Using dramatic reconstruction and archive footage, the programme depicts the excitement and fear of picket-line confrontation.
It reveals the intense strain on family and community and the twists and turns of Arthur Scargill's union, Margaret Thatcher's government and a police force in conflict with the miners.
The Miners' Strike is an analysis of an historic and bitter dispute that created turmoil in
thousands of lives and dramatically affected British society.