He was a knight of the realm, a friend of both Margaret Thatcher and the Prince of Wales, and a man known to have sexually abused a girl of 14. No, I am not referring to the late Sir Jimmy Savile, although he ticks all three boxes, but to Sir Laurens van der Post.

The reputation of this mendacious guru has miraculously survived the devastating exposé it received 11 years ago in an authorised biography written by J.D.F. Jones. Well, perhaps not so ‘miraculously’, given the sedulous attention his disciples have paid to burnishing his tarnished image.

Look him up on Wikipedia today and here is how the laudatory entry about him is headed: “Sir Laurens Jan van der Post, CBE (13 December 1906 – 16 December 1996) was a 20th-century Afrikaner author, farmer, war hero, political adviser to British heads of government, close friend of Prince Charles, godfather of Prince William, educator, journalist, humanitarian, philosopher, explorer and conservationist.”

Not a word there about the seamier side to his life which, most monstrously, featured his fathering a child with a girl who had been entrusted into his care on a trip from South Africa to England by her parents, only to be seduced at sea and then set up in London as his mistress in a bed-sitter in Sloane Square, conveniently handy for his marital home. He was in his mid-forties. The product of this union was disowned by her father. Her mother commented years later that Van der Post was “sick” and that “he knew how to pick his victims”. Sound familiar?

Only at the end of the Wikipedia entry under the heading ‘Posthumous Controversy’ does one read: “After his death a number of writers questioned the accuracy of Van der Post’s claims about his life. It was revealed that in 1952 he had fathered a child with a 14-year-old girl who had been under his care during a sea voyage to England from South Africa. His reputation as a ‘modern sage’ and ‘guru’ was questioned, and journalists opened a floodgate of examples of how Van der Post had sometimes embellished the truth in his memoirs and travel books. These and other facts were brought together in J.D.F. Jones’s Storyteller: The Many Lives of Laurens van der Post (2001), an authorised but for the most part hostile biography.”

The description ‘hostile biography’ is as carefully nuanced as ‘sometimes embellished’ (for which read ‘lied’). It would seem to suggest that Jones had set out deliberately to besmirch his subject. But it was not like that at all.

Jones, who died three years ago, was a distinguished writer and journalist, who was successively foreign editor, managing editor and southern Africa editor of the Financial Times. Asked by Van der Post’s family to write his biography, he began his task an ardent admirer of his subject.

I interviewed him some years after the book’s publication, when it was attacked by Christopher Booker in an entry on Van der Post he wrote for the Dictionary of National Biography. (As a dedicated disciple of Van der Post, he was not, you might think, the ideal person to supply a dispassionate assessment of his subject.) Jones told me: “When the book came out, the family were extremely upset. They insisted they were going to expose it as a malicious tissue of lies.

“They were shocked to discover they had a Hottentot ancestor — the first black woman to legally marry a white man in South Africa — who ended up an alcoholic prostitute. I lost friends because Laurens’s admirers and followers found it hard to accept the facts that I laid out. Booker writes that my book was ‘often inaccurate’ — a remark that is probably actionable. For all that he and the family have said, I am still waiting for a single error to be identified.

“I had three research assistants. After the first few weeks of work, we looked at each other and said: ‘There’s something wrong here.’.

“What we four had all discovered was that not a single word Laurens wrote or spoke could be believed. He was a total fantasist. I remember one researcher poring over military records and saying, ‘What is this about him being a Lieutenant Colonel? He was an acting captain.’.”

Among other of his spectacular lies was his career-moulding claim to have lived on intimate terms with the Kalahari Bushmen. “How long was he with them?” Jones asks. “From the inadequate diaries we have, it cannot have been longer than a fortnight. On this flimsy foundation, and an inevitably distant acquaintance with no more than 30 bushmen, Laurens would go on to build a substantial reputation.”

Then there were the friendships he boasted with, among others, Karen Blixen (of Out of Africa fame), D.H. Lawrence, Ernest Hemingway and Martin Luther King. Lies, all lies.

And that long-vaunted association with Carl Gustav Jung, deliciously suggestive of intellectual equality on both sides, turned out to have been a relationship whose intimacy was very largely of his invention.

As I said when first writing about Jones’s biography: “As one reads on, bug-eyed at [the book’s] revelations, one quickly realises that a superfluous ‘v’ appears to have crept into its title: Storyteller: The Many Lives [sic] of Laurens van de Post.” Strangely, it was as late as page 359 that Jones actually bit the bullet and called his subject “a compulsive liar”.

That he was such was acknowledged by Victoria Glendinning, in her 2006 biography of Leonard Woolf, an early publisher of Van der Post’s work. She called him a “fantasist and mythomane” and referred to his private life as “coarse and lascivious to the point of criminality”.

Her verdict is a sound one. At a time when much is being said concerning the need to rescind Jimmy Savile’s knighthood, here surely is another man undeserving of so signal a mark of merit.