HE was one of spy novelist John le Carré’s people – a character who charmed those around him but highly duplicitous by nature. You trusted him at your peril. But unlike author John le Carré’s similar characters in his books – with outward charm but no integrity – Ronnie Cornwell was not a made-up fictional figure. He was his father.

Ronnie, like his famous son whose real name is David Cornwell, was born in Poole, the son of respected Alderman AEF (Frank) Cornwell, believed to be a builder by trade and one-time town mayor.

But Ronnie’s shady ruses created a scandal that brought shame on his family and he found himself behind bars.

Today John le Carré’s acclaimed novel Tinker, Tailor, Soldier Spy, the subject of a TV series that enthralled viewers in 1979, has been made into a film, directed by Tomas Alfredson (whose previous films include Let the Right One In) to be released in September.

It features an impressive cast including John Hurt, Benedict Cumberbatch and Svetlana Khodchenkoval .

Gary Oldman stars as George Smiley, the part played so successfully on TV by Alec Guinness who spent part of his childhood in Bournemouth and Poole.

Le Carre, too, spent a good deal of his childhood in Poole where his grandfather, Alderman Cornwell, and grandmother lived in Parkstone.

In 1927, the year Ald Cornwell became Sheriff and subsequently Mayor of Poole, their address was Bournemouth Road but, by the time David Cornwell was born in October 1931, their home was at 5 Mount Road, near the Seaview viewpoint.

That year, David’s great-grandparents, Alfred Joseph Cornwell and his wife lived next door.

Ald Cornwell was a respected man, the senior partner in F Cornwell and Son insurance brokers, managing director of a Boscombe firm of motor repairers and a preacher at Loch Road Baptist Church in Parkstone.

David and his elder brother Tony frequently stayed with their grandparents in Mount Road and later when Alderman Cornwell and his wife, Elizabeth, moved to nearby St Peter’s Road, in a house demolished this year.

David’s father, Ronnie Cornwell, was married to Olive, the much younger sister of Alec Glassey, the MP for East Dorset from 1929 to 1931, who lived in Penn Hill Avenue.

They had met when the MP was presenting prizes to a football team and Olive pinned the badge on Ronnie, the tall centre forward.

With his gift of the gab and guile, Ronnie persuaded Alec to allow him to visit their home on the pretext of visiting a maid... but with his sights set on wooing the Glassey’s sister, despite her being above him in class.

Glassey, recalled le Carré when we met for lunch in Parkstone 12 years ago, was a stern, tall, forbidding man.

Ronnie – who had three doting sisters – by contrast was intent on living the good life. He spoke originally with a Dorset accent but over the years did all he could to lose it as he courted a champagne lifestyle.

As the years progressed, he was often to be seen in his chauffeur-driven Bentley, mixing with actors, football club directors, Test cricketers, snooker kings and politicians.

Ronnie would offer lavish hospitality but often would not have the money to pay for it.

But back in those early days, something happened involving him that scandalised the family.

What was it?

“I believe my father’s problems date from 1929,” le Carré told me when we met for that lunch years ago. “I don’t know the details of what happened but it was a spectacular local scandal and a very painful one for my grandparents.

“It was to do with an insurance fraud but I’ve never seen it in the papers.”

Was he right? Evidence suggests the scandal happened not in 1929... but five years later.

In 1930, Ronnie, was living with Olive and their baby son Tony in a house called Ambleside in Brownsea View Avenue, Lilliput which they occupied until 1933. (David – the future John le Carré – was born there in 1931.) At that time, Ronnie was still evidently a respectable local figure in Poole for in 1930 he was appointed chairman of the Poole Round Table.

His bent dealings, however, had caught up with him by 1934.

In February of that year he appeared in court at the Winchester Assizes charged with forgery... and was sent to prison.

What had he done? By the turn of 1934 Ronnie was running a firm in Exeter.

According to the court reports in the Daily Echo and the Bournemouth Directory, he was 25 at the time – though that does not tally with the age of 69 that was given when he died in 1975. A slippery man to pin down.

The case concerned a banker’s cheque for £215 4s (£215.20). Mr R Holt prosecuted and Ronnie conducted his own defence.

The court heard that Ronald Thomas Archibald Cornwall was a claims assessor based in Exeter and that the alleged fraud involved payments to a man called Walter A Tonkin who had been injured, along with another man, in a motorcycle accident in Cornwall.

Through trickery, compensation payments were diverted to Ronnie’s firm... though the defendant denied any intent to defraud.

The complicated case ended with Ronnie being sent to prison for six months, with the judge hoping it would be a lesson for him. It wasn’t.

Years later, when Ronnie was standing as a parliamentary candidate in Great Yarmouth, David found out for the first time that his father had been in prison. Ronnie gave him an explanation.

“He said: ‘Many years ago I was in the position of office boy who borrowed a few bob from the stamp box and caught before he had a chance to put them back’,” the author told me.

That dovetails with the trial account, for a police inspector told the Assize that “enquiries made it clear that it had been a question of robbing Peter to pay Paul.”

There had been nine other complaints but on those occasions the money was paid when police inquiries had been made.

Was this jailing the scandal that rocked the family?

A son being sent to jail for six months was shocking enough for such a respectable family.

And it was more serious than anything that had previously happened for the judge was told Ronnie’s record showed he had been fined for “aiding and abetting in the issuing of an insurance certificate that was false”.

But worse was to happen.

For while Ronnie was serving time – reported to have been mainly in Winchester, Exeter and the Scrubs – he was further prosecuted.

Details of that second case are unknown but, according to a subsequent bankruptcy hearing against Ronnie in 1936, the allegation was “that he obtained money by false pretences.”

And he was sentenced to “nine months’ hard labour”.

Ronnie later claimed he had defended himself brilliantly in a court – was it at this hearing? – against a young advocate called Norman Birkett, who later became a great barrister an a politician and served as a judge.

Was Ronnie’s claim true or a fiction? Either way, Ronnie had done his time when his bankruptcy hearing took place in Bournemouth in the summer of 1936. That hearing heard that he had been in business with his father in Bournemouth as an insurance broker and then went in for property transactions as well as having dealings with certain motor coach proprietors.

He owed £19,714,7s 1d.

That was a fortune in those days when the average salary was below £190. But his dishonest character was to see him in court trouble throughout his life.

A womaniser, as well as a classy conman, Ronnie returned home one night when David was five years old to discover Olive had crept out, leaving him and the children, never to return.

Many years later, when he was an adult, David got back in touch with his mother, living in Ipswich, through Alec Glassey.

Ronnie’s two sons went to boarding schools, often coming to Poole for their holidays where their aunts, Ruby, Ella and Doris, would look after them handsomely during their stays.

David was sent to Sherborne School in Dorset – he hated it – and, later, to Oxford.

He taught at Eton, worked for MI5 and MI6... and became one of Britain’s finest novelists with books like The Spy Who Came in from the Cold and The Constant Gardener to his (le Carré) name.

And often he and his wife, Jane, would return to Parkstone to see his adoring aunts.

And Ronnie? A classy conman (once declared bankrupt owing more than a million pounds in the 1950s), he lived a picaresque lifestyle, high-rolling, organising grand benevolent gestures – such as bringing the world-class West Indies cricketer Sir Learie Constantine to play in two matches in Poole Park in the 1950s – owning racehorses (often named after his children or, in code, his mistresses) and mixing with the rich and famous.

He fathered other children, including the actress Charlotte Cornwell, and occasionally served spells in jails as far apart as Jakarta and Zurich.

Yet, despite having few inner values and leaving a trail of victims, he remained, to outward appearances, a respectable man with a gift for self-delusion.

Untrustworthy by nature (he once even threatened to sue his own son and to demand repayment for the money spent on his education) yet he was adored by friends surrounding him.

But he left victims in his wake, including, it has been said, his freshly-bereaved mother.

He died in 1975 having once reportedly said: “David can never escape the fact that he is my son and I his father.”

John le Carré – David Cornwell – who now lives with his wife, Jane, in Cornwall, based his fascinating novel The Perfect Spy on his father who lived in his own secret, mendacious world.

“Ever since I began writing and long before I was published I have tried to write about my father,” le Carré once wrote.

In totally contrasting ways, both Ronnie and his famous son have earned their living by story-telling.

And all John le Carré’s life, as someone once observed, Ronnie has been “the monkey on his back.”