Zoe Paskett talks to a writer whose mother’s death 50 years ago was shrouded in silence, until he got the courage to go in search of her.

“I think I became a writer to write this book,” says Jeremy Gavron.

“You become a writer to tell the stories that other people don’t tell. This was my story.”

His mother Hannah was 29 years old when she dropped off her youngest son at nursery, locked the door of her friend’s kitchen and turned on the gas.

The circumstances of her death in 1965 bear striking similarities to that of Sylvia Plath three years earlier: both writers born a year apart with two young children, dying two streets away in Primrose Hill.

But while Plath had a history of mental illness and suicide attempts, Hannah’s death was unexpected. To those on the outside, she was a happy, successful privileged woman, with a book two weeks away from being published.

A Woman on the Edge of Time (Scribe £16.99) is Jeremy’s memoir of his mother. Just four when she died, he has no memory of her; only the moment his father sat him and his older brother on the end of her bed to break the news that she was dead.

Gavron grew up in Highgate in the shadow of his mother’s death and the silence that surrounded it. His father remarried (former London deputy Mayor Nicky Gavron) he had two half sisters, including film director Sarah Gavron. But no-one spoke about her, except for a few snippets from his grandmother.

“The family narratives, how you’re taught to be and think by who you’re around, meant I’d been taught to think this was a private hidden story, so the thought of writing about it never occurred to me.”

Strongly affected by the sudden death of his brother from a heart attack 10 years ago, he developed a burning curiousity to find out about their mother’s life and the circumstances of her death.

“My grieving for him was complex. We were good friends but we had a difficult relationship. I felt this sheer force of emotion coming up in me and although I’m quite sceptical, I did think this was some ancient, buried grief.”

Over seven years, the Hampstead resident tracked down around 70 people to piece together an image of the mother he never knew.

“Even taking as objective a view as possible, she was a remarkable person. She seemed to be very good at everything. She was smart, she was athletic, she could act, she was very charismatic, driven.”

Hannah left school at 16 to attend RADA and on leaving, married barrister Robert Gavron, when she was 18. She studied sociology at Bedford College, and taught at Hornsey College of Art in the years before her death.

As an academically minded woman in the 50s and early 60s, Hannah encountered obstacles from male colleagues, from deliberately delaying the release of her sociology thesis, to denying her a job because she wore too much eye makeup.

“I think that for a smart, ambitious, yearning woman at the period of time, the male dominated world made life very difficult.”

Her struggle was apparent in the title of her book, The Captive Wife, which documented interviews with almost a hundred young, unhappy north London mums.

Published posthumosly it gained wide coverage from national newspapers, as an immensely important book “in terms of human happiness”.

“She was experiencing difficulties herself and her mind was also full of those women. So when her hope died, the world must have seemed a bit of a hopeless place for a woman.”

Despite taking it off the top shelf and opening it on multiple occasions as a teenager, Gavron didn’t read the book until a few years ago, nervous of what he would find.

“I think I was afraid of the accusation in the title. I think lots of men are afraid of feminism and I certainly was. I felt threatened. I’d read the introduction by Ann Oakley, a fierce feminist, and I could sense her sort of saying that men killed [Hannah] and I didn’t like that idea.”

To an extent, he says, it’s true. A combination of her failing marriage and the struggle against a misogynistic society contributed to her pain.

“It’s like a perfect storm – a load of things come together at the same time to push you over the edge.” Gavron’s book is an emotional and personal journey of discovery. Still receiving calls from people who had known Hannah, he knows it’s not the end of his exploration, but feels that writing the book has begun a feeling of release.

“I can’t shake off the feeling that I’ve broken a taboo. I really hope this book will reach down to the grandchildren because suicide casts a long shadow.”