As crime series Prime Suspect celebrates its 30th anniversary, creator Lynda La Plante reveals how she'd like to bring DCI Jane Tennison back.

Lynda La Plante is contemplating how she would like to bring her dogged detective DCI Jane Tennison, originally played 30 years ago by Helen Mirren, back to life. "I've been asked this so many times. I thought, 'What is she doing now?' She's past retirement age. I've started a novel, but she's retired."

La Plante reveals Tennison may be brought out of retirement to investigate a cold case. "I'm working on it. It's on the back burner. I'd love it for the screen. I'd love to meet Helen and say, 'Come back now! One more time, Helen!' But she's so hugely successful and such a big movie star now that I don't know if she would be interested. It would be wonderful, though."

La Plante may be 77, but the former actress from Liverpool, creator of Prime Suspect and Widows, author of the novelisations which followed, plus a string of young Tennison books and stand-alone thrillers, shows no sign of slowing down.

The bestselling author and scriptwriter has only been out of her home in Surrey to walk the dog and do a bit of grocery shopping for most of the past year, and recently had her first Covid jab, but the solitude hasn't stemmed her creative juices, hard-working ethos and wicked sense of humour.

She's been positively productive during the pandemic, written two books - Judas Horse, the second in a new series featuring hapless detective Jack Warr, and a new young Tennison novel, Unholy Murder, out in the summer - and is about to launch the second series of her forensics podcast, Listening To The Dead (on Feb 24).

"I'm so used to being solitary in writing that it's galvanised me. I'm like a lunatic. I can't stop!" she enthuses. She's also hoping to make a number of appearances to celebrate Prime Suspect's 30th anniversary, pandemic allowing.

The series broke barriers on its release, as Tennison battled sexism and prejudice in a male-dominated profession, refusing to be undermined by colleagues who questioned her seniority and ability. It ran for seven series, from 1991-2006, although La Plante bowed out after series three to pursue other projects.

She recently found the original Prime Suspect script she had written, inspired by the experiences of ex-Flying Squad officer Jackie Malton. It cast Mirren as DCI Tennison, the first woman in the history of the Met to lead a murder investigation after years of being overlooked, and aired in April 1991. The novelisation followed that year and is still in print.

"I had a terrible time with her name because you are not allowed to call a TV detective by the name of somebody already in the force. I could never have called her the name of the policewomen I know. You have to find a name that is not in the ranks of the Metropolitan Police," La Plante recalls.

"She started off as Brownlow, but there was already a Brownlow. But I always loved the poet [Alfred, Lord] Tennyson's work - and thought, 'Nobody's going to be called Tennison in the Met', and they weren't." She never anticipated the huge success of the series, which won a clutch of Baftas and Emmys for cast and creators.

She always had Mirren in mind for the part, she recalls. "It was quite a fight. The [TV executives] were very much bringing up names [of actors] who were completely wrong for her. I kept saying no.

"Then I was met with, 'Well, I don't know Helen's work - has she done a lot of TV?' I said, 'No, she's a great theatre and film actress, she's the right age to be a DCI.' Thirty years ago there were only three high powered female Detective Chief Inspectors in the Met."

La Plante parted company with the TV detective after the third series and was not impressed at the way the character turned into an alcoholic battling her demons, the older woman who had sacrificed everything for her career, struggling to solve her last case before retirement.

Today, she says: "My hope for the character was that she would become commander, which is the reason why I walked. I didn't want her to be an alcoholic. I didn't want her to lose her way. She'd come so far and lost so much of her love life, I didn't want her to become an alcoholic and prove she couldn't cope. Every woman I'd met who had reached the top coped magnificently."

It's no secret that over the years La Plante has conducted painstaking research into her subjects. She's graced the tiled floors of mortuaries, witnessed numerous post mortems and is an honorary fellow of the Forensic Science Society.

She has amazing contacts she can call on for all sorts of minute details pertaining to crime and the changes in investigative practices. "The mobile phone can lead you to a killer, CCTV is everywhere these days - and then there are computers. And I'm so cack-handed with them! My son [she has an adopted son, Lorcan, 17] fortunately, is an IT expert."

In 2015, La Plante brought back the detective in the first of a series of prequel novels as young Tennison, rewinding to the Seventies as the eponymous 22-year-old newbie WPC is drawn into her first murder case.

Despite falling out with ITV executives over creative differences concerning the 2017 TV adaptation, Prime Suspect 1973, which was axed after one series, La Plante has continued to pen her young Tennison novels, with Blunt Force, number six in the series, about to come out in paperback. "I'm taking the young Tennison through the Seventies when she's just out of training school, up through the Eighties and Nineties to the point where she becomes DCI Jane Tennison.

"I'm able to construct her life, her disappointments, failures and dogged persistence. It's been very informative to go back to talk to women who were officers then. Which means Prime Suspect is constantly in my brain."

In the 30 years since she penned Prime Suspect, many things have changed. The Met, for instance, now has its first female chief, Dame Cressida Dick, who she has met.

Yet sexism hasn't been totally eradicated, La Plante observes. While women are better represented within the Met, she says that the women officers she knows say sexism still exists, only it's more covert.

"Sexism, as well as competitiveness [exist], but women have broken through, you can't keep them down. It's just that they are learning how to deal with it. Plus, in a team of officers, you daren't have any form of discrimination or sexual harassment on show, but it is there, it's just underneath."

What would DCI Tennison make of the world today? "I think she'd take it in her stride," La Plante reflects.

And then we're back to the possibility of Mirren returning to the role that made her a household name. "I keep in touch with Helen Mirren, mostly on a congratulatory basis. She might be tempted to come back, you never know. And if it's a good enough and strong enough storyline, maybe she would be interested."

Blunt Force by Lynda La Plante is published by Zaffre in paperback on March 4, priced £8.99. Judas Horse is published by Zaffre on April 1, priced £14.99. Prime Suspect is published by Simon & Schuster, priced £7.99 paperback.