I was nearly 40 when I discovered that I had an older brother. My lifelong family position as the eldest of four evaporated in a flash one Sunday afternoon in 2008 when my mother called us all together at her house, saying she had something she needed to tell us.

She opened a box file and with trembling fingers pulled out a black and white photo of a baby. It turned out that my mum, who died suddenly and unexpectedly of Covid in February of this year, had been one of a number of unmarried women — there could be as many as 250,000 — forced to give up their babies for adoption between the 1950s and 1970s.

This tragedy is only just coming fully to light as the women whose babies were taken, now in their seventies and eighties, are being asked to give evidence to a new investigation. The scandal has been declared a human rights issue by Harriet Harman, chair of the Joint Parliamentary Committee on Human Rights. An official inquiry has now been launched and the committee is urging birth parents to come forward.

I have no doubt that if my mum was still alive, she would have wanted to contribute towards helping people understand the magnitude of what happened to her and so many others. As she spoke on that Sunday afternoon, some bits of her story we already knew. How she had met our dad, an immigrant from the West Indies, at the Avery Hill teacher training college in south-east London in 1966 and was instantly smitten. How my mum’s family disowned her for ‘bringing shame’ by dating a black man. All this was part of our family folklore, but as for what had happened next, we’d been completely in the dark.

Mum described how — in the summer of 1967 when she was 20, cast out by her family, unmarried and extremely naive — she found herself pregnant. Only then did she realise the gravity of her situation.

‘Your dad,’ she explained, ‘had talked about marriage, but he simply refused to propose to me. Suddenly I was on my own.’ The 1960s may have swung for some, but for ordinary women, it was still a time of powerlessness and repression, redeemable only by having a man to advocate for you. The Abortion Act of 1967 would not come into effect until April 1968, so the only option for her was to tell absolutely no one and hide away as her bump became more obvious. As her due date drew closer, she entered a religious-run home for unmarried mothers.

She said that the nurses in the home were not overtly unpleasant, unlike in the case of the former MP Ann Keen, who was deliberately denied pain relief during labour as a punishment. But there was an all-pervasive sense of shame: the feeling that my mum had brought it all on herself by being a silly, immoral, irresponsible girl.

She hoped against hope that my dad would change his mind about marriage once the baby was born. But if anything, she said, his opinion hardened. Instead of braving society’s wrath and deciding they would raise their baby together, he insisted on the ‘clean break’ of adoption before their relationship could continue as before. They would become engaged and married once ‘this mess’ had been tidied away.

My mum loved her little baby boy — nicknamed Pedro by the nurses as he looked ‘so foreign’ — so much. She breastfed and spent hours gazing at his face as he slept. She nuzzled his neck and breathed in his scent so deeply that she thought she might faint.

She knew he had to go — the nurses reminded her constantly — but she still hoped that someone, somewhere, would come to her rescue. One day, while the baby slept, she was called to one of the nurse’s offices for a chat. When she got back to her room, Pedro was gone. Mum said that the disbelief that it had actually happened hit her like a sack of rocks. The nurses said she must pull herself together and be grateful that her ‘problem’ was solved.

Six months later, in June 1968, she and my dad married, and they went on to have us four. They divorced in 1995 and my dad developed dementia, meaning that the decision of what to do with this secret was now entirely hers.

Mum got us together on that Sunday afternoon because a recent change in the law meant that parents had the right to trace adopted children, rather than only the other way around. Not long afterwards, Pedro was located by the adoption agency and Mum’s letter was passed on. But the message came back that he did not wish to pursue further contact, so that was that.

When my first baby — a boy — was born just a few years before Mum disclosed her secret, I’d felt a strange, unspoken disconnect with her. When I found out about Pedro suddenly I could see how hard it must have been, watching her daughter give birth to a son, what silent grief it must have triggered.

It also helped to explain why Mum stayed with Dad for 28 years and kept having children. She was an intelligent and courageous woman and my dad was often violent, but they shared the secret of Pedro. It’s also now widely understood that women who have had a child taken away will often go through life desperately trying to replace them, no matter how unsuitable the situation.

My mum prayed every day that Pedro would change his mind and agree to meet her. He never did. She never got to hold him and explain that she didn’t give him away, he was forcibly taken. She never got to describe how every year, on his birthday, she would bake a cake with us, her other children, never telling us what the cake was for, just silently wishing he was there. She never got to show him the tiny mittens and booties that she knitted, and which were left in his cot by the nurses as they took Pedro from her for the final time.

Covid robbed her of her life, just as government policy, public shame and the failure of a man to step up robbed her of her son all those years ago. As for an official government apology, I firmly believe that history cannot be rewritten, but listening to the brave women who’ve spoken publicly about their own experiences, I hope that the government investigation helps deliver the acknowledgement they need. My mum would have appreciated that — and really, it’s the very least these women deserve.