Two twin sisters discovered they have different fathers as their DNA kits laid bare the truth of the only ever documented case of its kind in the UK. 

Michelle and Lavinia Osbourne, both 49, have always shared a special bond as twin sisters after being ushered into the world by a vulnerable 19-year-old.

Their mother, who gave birth to them in Nottingham in 1976, had spent her life in and out of foster care and suffered abuse at the hands of her stepfather. 

And when the twins would query about their parentage, she would say their father was a man named James, who was largely absent from their lives. 

But when he returned to their lives as teenagers after Lavinia tracked him down, Michelle had doubts about him being her father. 

And after their mother developed early-onset dementia in 2021, and could not answer their questions, Michelle found a photo of James, which only furthered her doubts. 

'I just thought, you don't even look anything like me,' Michelle told the BBC Sounds show, The Gift. 'So I bought myself a kit.' 

At home, DNA kits can reveal a range of aspects about your heritage and health, but Michelle did not consider how her results would impact her twin. 

Meanwhile, the results, which would change the sisters' lives forever, arrived on the very same day that their mother passed away on February 14, 2022. 

When she opened her results, Michelle's doubts were confirmed - James was not her biological father. 

Instead, after weeks of investigating, she found her father was Alex, a sibling of a woman who was their mother's friend. 

In a bid to connect, the 49-year-old contacted her father's family, who, in turn, warned her of his struggles with substance and alcohol addiction over the years. 

However, when the twins met with Michelle's paternal cousin, she felt an instant connection - but doubts quickly rose to the surface for Lavinia. 

In pursuit of answers, she also ordered a DNA test amid growing feelings of uncertainty that she was not related to Michelle's father, Alex. 

But when she opened her results, she was left both stunned and furious to discover her twin was actually her half-sister. 

'I was angry with Michelle for having me go through this, because I just didn't want this reality,' she said. 

The 49-year-old twins are a result of an incredibly rare biological process known as heteropaternal superfecundation. 

It requires a woman to release more than one egg during the cycle, with both having to be fertilised by sperm from different men, and survive the pregnancy. 

There have only been 20 cases of heteropaternal superfecundation found throughout the entire world. 

However, Michelle and Lavinia are the only set of twins in the UK ever to have been documented as having different biological fathers.  

And while Michelle was not taken aback by the revelation, Lavinia was left crushed by the development. 

The two had shared a difficult childhood of instability, often moving from different homes and carers, only having each other as a constant.  

'She was the one thing that belonged to me, the one thing that I was certain about, the one thing that I was sure of,' Lavinia said. 'And then she wasn't.'

'I wasn't surprised,' Michelle added. 'I'm still in amazement that this can actually happen – it's super weird, super odd, super rare – but it makes sense.'

But there was another surprise in store for Lavinia upon opening her DNA results, not only was Alex not her father, but neither was James. 

Initially, she had no desire to find her father, but her sister Michelle was insistent on getting to the bottom of it. 

Eventually, they discovered her father was Arthur, a man living in west London, whom her mother turned to in a time of need.  

She found he was 'an exuberant character', similar to her, and now visits him often with Michelle. 

'I feel like I've found a place to belong, and that place is with my dad. He has told Michelle that she, too, can call him Dad,' Lavinia said. 

Meanwhile, Michelle did eventually meet her own father Alex via her new family members, but she says he was 'under the influence of drugs'. 

And while she recognises he is her biological father, she does not want to pursue a relationship with him in the future, satisfied with the fact that she now knows. 

The sisters will never know if their mother knew they had different fathers, but suspect she may have felt something 'in the back' of her mind. 

The two had always known their differences, being non-identical twins, the results initially made those more apparent - but their unique bond has stood the test of time.

Describing them as 'miracles', Lavinia insisted their closeness could never be broken, while Michelle agreed, adding: 'She's my twin sister. Nothing takes away from that.' 

The full box set of The Gift is available now on BBC Sounds. The series starts on BBC Radio 4 on Tuesday, 5th May, at 0900.