Belgian detective who met his end in Curtain to follow in footsteps of Bond and Holmes after Agatha Christie estate commissions Sophie Hannah to write new Poirot novel

There are a few clues to exercise the little grey cells – it will be set vaguely in the late 1920s, after the shocking French train strangling business and before the well-timed fireworks at End House in Cornwall; and there will be no Captain Hastings. It is bound to have a twist and it will certainly be the first and perhaps only Poirot book not written by Agatha Christie.

The author's estate and publisher HarperCollins has announced plans to follow the examples of James Bond and Sherlock Holmes by reviving one of British fiction's most-loved characters in the hands of a new writer.

Sophie Hannah, the bestselling writer of contemporary psychological crime thrillers, is to write a new Poirot novel 93 years after Christie first introduced him in The Mysterious Affair at Styles and 38 years after she killed him off in Curtain.

Hannah admitted feeling nerves. "Anyone who wasn't daunted by a project like this would have to be insane," she said. "Agatha Christie is the greatest crime writer of all time and it is a huge, huge honour for me to be the person chosen to do this. I do have a sense of trepidation but I don't think I'd be able to write the best possible book if I didn't, if I was at all complacent about it. The fact I wake up every day knowing I have this incredibly important mission to fulfil will hopefully make me write a better book."

Hannah said she'd had a crime plot twist idea for about two years but had not been able to make it work in a contemporary thriller – but it could work, she hoped, in a Poirot-esque detective novel.

She won approval after presenting a detailed 100-page outline to the publishers and Christie estate; the book, yet to be titled, is to be released in September 2014.

Mathew Prichard, Christie's grandson, said it was not a decision they had come to easily. They had watched Sebastian Faulks write a new Bond novel with interest but "we thought that wasn't for us because, apart from anything else, my grandmother wrote a lot more books than people like Ian Fleming. We thought there wasn't enough room in our canon."

The estate has had a change of heart, though, won over by arguments that it will lift interest in the Christie list as a whole and, Prichard hopes, be "a huge shot in the arm for the whole detective and mystery section".

Of course it is impossible to know how Christie would have felt about it. "All authors would rather write their own books themselves," said Prichard. "But I hope the arguments would mollify her – she really did care that as many people as possible in as many countries as possible read her books."

Hannah's book will not feature Poirot's best friend Arthur Hastings and will be set roughly between The Mystery of the Blue Train (1928) and Peril at End House (1932).

Christie wrote 33 Poirot novels – the final one, Curtain, was written during the blitz and locked away in a bank vault to make sure there was a fitting end to the series. Curtain was published in 1975 shortly before her death. That adaptation is one of four still to come on ITV1 with David Suchet taking on the role of the vain but brilliant Belgian detective for the final time.

Prichard said the estate and publishers were not likely to follow the same path with Christie's other detective, Miss Marple, nor would they necessarily commission more than one new Poirot. "I think we will advance cautiously in this particular field."

Both he and Hannah hope that even diehard resisters will be won over. "I regard every word Agatha Christie ever wrote almost as a holy text, so I'm not going to be taking any liberties," said Hannah. "He won't be taking up rollerskating.

"I know some people will say, 'Once a writer's dead, leave their characters alone.' But so many famous dead writers are having this done – James Bond, Sherlock Holmes – it becomes a kind of weird omission if Agatha Christie doesn't have that done for her. It almost feels it needs to be done. I think it is great that beloved characters from fiction don't have to die."