The man behind a major political scandal over the introduction of child benefit has finally been revealed.
Malcolm Wicks, who subsequently entered politics and became a Labour minister, has admitted in posthumously published memoirs he was the civil servant behind the unauthorised release of Cabinet discussions about child benefit in 1976.
The leaked minutes revealed James Callaghan's Labour government used "downright lies" in a bid to drop the proposed introduction of child benefit.
Public outrage at the revelations contributed to the Callaghan administration's failure to block the introduction of the payouts, which have subsequently left parents nearly £400 billion better off.
Wicks wrote in his autobiography, My Life: "As days passed and I saw more documentation, including Cabinet papers, it was not so much the attempt to abandon child benefit that incensed me, but more the way it was being done: the manoeuvring, the downright lies and the attempt to play off Labour MPs against trade union bigwigs.
"My view was that if a Labour government was to abandon its policy, having connived and misled, then I had a duty to leak what happened to the papers – knowing full well that this would have repercussions – so that people would see the truth."
Wicks entered parliament as a Labour MP in 1992 and joined the New Labour government as a junior minister in 1999.
He rose to become energy minister and was judged to have been a "parliamentary angel" in the expenses scandal.
Frank Field, the Labour veteran, was the recipient of the leak in 1976 and revealed the story in an article for the left-wing publication New Society.
He said he referred to Wicks as 'Deep Throat' in a bid to try and keep his secret safe.
"Not only was there the embarrassment of the prime minister and chancellor misleading their colleagues in cabinet, in the unions and on the backbenches, but the papers had been wrongly reclassified as top secret," he wrote in a confessional article for the Guardian.
"If these papers could get out, was any government secret safe?"
Field admitted he burned Wicks' papers and his own diaries in a bid to protect his source, accepting he was likely to face surveillance.
"I accepted that my phone was tapped," Field added.
"A leak on this scale, with child benefit papers wrongly reclassified as top-secret in an attempt to stop the leak, meant that it was important for the government to find the culprits."
But the leak inquiry led by bomb-squad graduate Commander Roy Habershon failed to find the culprit and the mystery lasted for 38 years before finally being solved.
Child benefit has subsequently remained universal for all until the present coalition government decided to strip it from better-off families.