For two decades they patrolled the English seaside during school holidays, instilling fear into smugglers, kidnappers and spies, but in 1963 the Famous Five had their final adventure.

The fates of Julian, Dick, Anne, George and Timmy, arguably the most formidable upper middle class crime-fighting squad assembled, have been open to speculation ever since.

But now the mystery is at last about to be laid to rest with a new television series. The characters are scheduled to return to the screen as middle-aged men and women in a drama authorised by Enid Blyton’s estate.

Chorion, which administers the author’s works, has commissioned Twofour, an independent television production company, to develop a series that would put Julian, his brother Dick, their sister Anne and their cousin Georgina in their 40s and 50s. Timmy, the canine fifth member of the Famous Five, has long since died, but his bloodline has survived and he would be represented by one of his descendents.

The group no longer spends its summer holidays drinking lashings of ginger beer or investigating suspicious foreigners. The members have gone their separate ways, but are forced to regroup when they are confronted with a new crime.

A source told The Times that one idea was that the group would reunite to solve the murder of a family friend. “They would all be in middle age, perhaps some of them would be going through midlife crises,” the source said.

“It will be interesting to see whether the characters have grown up to be like they were when they were children. Would George, the tomboyish one, now be glamorous and have lots of children? Would Anne, the sensible one, be dysfunctional?”

George, whom Blyton based on herself, has been the subject of speculation in the past. The character, who wore masculine clothes and cut her hair short so that strangers would mistake her for a boy, is often assumed to have been a lesbian. A BBC Radio 4 series in 1995 suggested that she became a nurse who while not a lesbian, never married.

Members of the Enid Blyton Society welcomed the idea provided that it was faithful to the original stories. Anita Bensoussane, a moderator on the society’s web forums, insisted that a grown-up George should not be overly feminine. She said: “A complete character reversal would be too contrived. But a few surprises would be fine as long as they seemed plausible. I’d love to see a grown-up George sitting on a rock on Kirrin Island, emotions playing over her face as she read a letter she’d received from one of her grown-up cousins.”

Other society members hoped that the murder victim would be Edgar Stick, a brattish child who taunted George with rude poems.

Several Blyton enthusiasts went online to urge the programme makers not to send up the stories.

“The biggest danger would be the whole thing turning into another Five Go Mad in Dorset. The 1982 Comic Strip parody of the Famous Five was hilarious, but do we want to see it repeated 25 years on?”

Five Go Mad in Dorset, which starred Jennifer Saunders, Dawn French and Adrian Edmondson, spoofed the series by showing the characters expressing sympathy with Nazi Germany and scoffing at immigrants, homosexuals and the welfare state.

A source close to the production suggested that she would seek actresses of the calibre of Imelda Staunton, who won a Bafta in 2005 for her performance in Vera Drake.

An animated version of the Famous Five set in modern times and featuring the offspring of the original characters is scheduled to air next year.

Mix of characters gives winning formula

— George (Georgina). The tomboy. Has short hair, a fiery temper and likes to argue with Julian. Her greatest thrill in life is being mistaken for a boy

— Dick. The joker. Teases George (who is the same age as him) for wanting to be a boy, and Anne for being feeble, but can be brave. Brother to Julian and Anne and cousin to George

— Julian. The leader. As the eldest, he is responsible but also very bossy. He can be pompous and sexist

— Anne. The wimp. The baby of the group, very girly. She brings a domesticated touch, doing the washing up while the others are out solving mysteries

— Timmy. The dog. An uncommonly cunning pet, Timmy is an affectionate, loyal mongrel whose ability to protect and assist makes him more than just the team mascot

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