The secrets of lost luggage auctions: I bought four bags for £100. What would I find inside?

Unclaimed suitcases were once destined for landfill. Now people are suitcase gambling' - bidding for bags and their unknown contents, and diving deep into strangers' lives

A yellow suitcase draws me in like a beacon. It is stacked on a dark shelf at the back of Greasby's auction house in Tooting, south London, and looks brand new, with a hard exterior and wheels that Richard Stacey, a Greasby's regular who is dressed in shorts, a plaid shirt and a cream bucket hat, tells me to test. So I test them - and they work. If I was just buying a bag, that is all I would need to know. But this isn't just a bag: the zip is locked and when I lift it, it is heavy. This yellow suitcase is filled with a stranger's lost belongings. And I won't find out what is inside unless I submit a winning bid.

I write down the lot number, 281, and my bid of 70 on a form, along with four other bids - for a larger black bag that is filled to the brim; a sensible blue suitcase with a compass in the handle that I expect belongs to someone older; a small wheelie in Louis Vuitton-like check; and a smart piece of hand luggage that I assume must be a businessperson's. In all, I bid 250 for five suitcases - way too much - but Stacey has been to the auction house 10 times before, and tells me I probably won't win if I bid less than 40 on each.