We are now able to hand matters on to the authorities. Subsequent checks with the Home Office reveal that Reza appears to have entered Britain with a similar story to the one he told in France - a story at odds with the documents and information provided by Goli. An investigation is launched to get to the bottom of the claims made during the asylum process.

During the course of the investigation, we try to contact Reza to check on the welfare of Bru and to hear his explanation for his actions. To date he hasn’t responded.

We’ve reached a part of the story where respect for a little girl’s privacy means we won’t be able to reveal the rest of what happens in so much detail, but an ending of sorts is in sight.

Goli receives help from Angus MacNeil, a Scottish National Party MP, who has taken a particular interest in refugee issues. He agrees to start informal negotiations with Reza about giving Goli access to Bru.

Through talking to MacNeil, Goli accepts that whatever Reza has done, he’s the only parent Bru has known for more than half her life. “We need to think about what is best for the girls - and to let both sisters know the father and both sisters know the mother,” says the MP.

What happens longer term will be up to the authorities and is complicated by the fact that Goli has refugee status in Denmark. There is no automatic right for her and her younger daughter to settle in the UK even if she wanted to.

It’s just before Christmas and Goli and Baran have arrived at Liverpool Airport with a bag brimming with presents.

Rob and I pick them up and immediately Baran shows us her new swimsuit. Goli has brought the exact same one for her sister, but confesses that she didn’t know what size to buy. Bru was taken when she was three, and is now eight years old.

Messages are pinging on Goli’s phone, from her mother in Turkey and from Martin, the Danish refugee worker who has helped her so much. They’re praying that things go well.

As we drive to the meeting point, we spot Bru walking alongside her father, carrying her own bag of gifts for her sister. After all this time, Goli struggles to recognise her daughter by sight and breaks down. She can’t really believe this day has come. I hang back, not wanting to intrude on this very private moment.

Goli has been preparing herself for this day. She knows it will not be easy and she has to take a few moments to hold her emotions in check. She is nervous as she approaches Bru and senses the confusion as the little girl watches her approach. She stops herself and bends down, introducing herself - by name - to her own daughter.

For Baran there is no holding back and her joy is immediate. She runs straight over to her big sister and grips her in a hug, not letting her go. Before the reunion she’d talked of wanting to hug her sister and now her dream has come true. In her excitement she shows Bru her new swimsuit, and talks about how they can swim together in their matching suits.

Goli has been learning English so that she can be confident about talking to Bru, and at first they’re all talking over each other, with Baran's voice winning out.

Then the three of them find a way of connecting, both ordinary and yet so powerful - they brush each other’s hair and Bru gathers her mother’s curls into little bunches.

Midway through that reunion Goli leaves her daughters playing together for a few moments. She calls me and says that the emotions she’s experiencing are so strong that she needs a few moments away to reflect on what’s happening. She doesn’t want to overpower Bru with the force of her feelings and she’s trying to keep the conversation relaxed and upbeat.

When Goli finally returns to the car, after a meeting with Bru lasting a couple of hours, she is euphoric - showing me photos and a video she's taken on her phone of Bru and her sister playing together. She's already sent them to her mother, her sister and to Martin.

She says it felt like Bru had no memory of her and this was hard to cope with: “She was totally unprepared. She doesn’t have any background of her mother. She thinks, ‘My mother is not alive and I don’t have any mother.’

“She tried to come close to me. It was incredible to see her for the first time. I can see how much she’s grown up, how beautiful she is, how independent she is and so I don’t feel too sad. I can forgive something.”

It’s been a remarkable journey for Goli. She describes her past life in Iran as being like a kind of prison, an existence where she had no say or control and where her only joy - her life as a mother - was cruelly ripped from her. She says she has changed so much.

“I didn’t know I had this power inside me. Now the feeling I have as a woman is very good. It’s beautiful. I have choices, and I can take responsibility for my decisions.”

For Goli this isn’t an end - far from it. There is lots of work that must take place to rebuild the relationship she lost.

“That is my dream now, to look after my children. To start to make this relationship. I really want to try and stand up strong. I can give her a beautiful life - she deserves that.”

Although he was so angry at being lied to by Reza, Rob now feels less strongly. He says he can forgive Reza and is sure that over time Goli will be able to rebuild her relationship with her daughter.

Rob has done what he set out to do - intervening very personally in the refugee crisis, in his own small way. However good the systems are for coping with refugees, the authorities can never hope to get to the bottom of all these stories. I’ve learned that, amid the chaos, the truth can be easily obscured.