“So, I just had to hide in a safe, or more like a vault downstairs,” he said, moments after escaping Hour House in Marylebone.
“I was in there picking up this vintage piece that I’ve been waiting for, for ages and these guys drive a scooter through the glass and start battering the shop with hammers, with huge hammers, wearing helmets.
He added, “We’re in the back of the shop looking at them, sprint downstairs (and) hide in the vault until all the noise passes.”
Spencer is the younger brother of Pippa's husband James Matthews, and is the founder of Eden Rocks Diamonds, which is named after his family's famous St Barths resort Eden Roc.
He's also married to Brian McFadden's ex-wife Vogue Williams, with whom he shares a one-year-old son Theodore.
After sharing a series of shocking photographs from the crime scene, he posted another to his Instagram stories of himself wearing the vintage watch he'd procured.
“Amongst all the rubble and all the glass and stuff there’s one watch in the entire shop and it’s mine,” he explained.
“Now, if that’s not luck, I don’t know what is!”