‘The last sighting of her was when she left her room at the Sir Stanford Hotel on Market Street. She was seen on the CCTV footage in a hallway at around 5 a.m. and she was seen leaving the foyer and walking into Market Street at around 5.10. That’s where we lose track of her. I understand people could not see more than a foot in front of themselves for most of the morning. And I realise that everybody in this situation says this, but it’s completely out of character for Mum not to be in touch, and so all this is obviously very worrying for us.’

Detective Croft said, ‘You’ve got photographs of Agnes Moore in your press packs, guys.’

I opened the manila folder the female copper had given me on the way in. There were two sheets of paper inside, stapled together: the first one had Mrs Moore’s stats on it – hair colour, eye colour, age – and the second one was a copy of a recent photograph, showing Mrs Moore all dressed up for a wedding. If you’ve followed the case at all, you’ll know exactly which photo I mean: she’s got a skirt-and-blazer suit on, made of a kind of brushed, burgundy satin, like a mother of the bride might wear, and a hat with some netting. She’s holding up a plate with a big piece of wedding cake on it that’s covered in an inch of white icing, and she’s making a funny face, like she can’t wait to stick her fork into it.

It’s a really nice photo. In other words, your ordinary, happy British grandma, having a good time at a family wedding.

Once we’d had a few seconds to study the picture, Detective Croft called for questions. I tend not to jump in on such occasions, in case I give away what I’m thinking and, therefore, my scoop. So the first question was from one of my News Limited colleagues, a Telegraph reporter who wanted to know, ‘What was your mother doing in Sydney, Ms Moore? Was it a holiday?’

That’s where things got a bit more interesting, obviously. Ruby said, ‘It was a holiday but it was quite a special holiday. Mum was actually in Sydney to meet up with a sister she hadn’t met before . . .’

That stopped most of us reporters in our tracks.

Sisters who hadn’t met before? What was that about?

Ruby said, ‘I should explain: Mum was born in London but she was placed in an orphanage near Manchester fairly soon after birth. This was in 1940, the war was on, so it was probably for her own protection. She spent seven years in that orphanage and for a long time we assumed that Mum’s parents must have been killed in the war, or perhaps her father had to go to war and hadn’t come back . . . We didn’t really know what the story was, but then, just a year or so ago, Mum received a letter from a lawyer here in Australia saying that her parents hadn’t been killed, they had actually got married after the war and they’d come out here and raised a family – they’d had another little girl, a girl called Snow. So that was very exciting for all of us, the fact that Mum had a sister in Australia, and of course she made arrangements to come out and meet Snow as soon as she could.’