Mobile phones, wallets, rucksacks, spectacles and keys top the list of the 6,000 items that arrive weekly at Transport for London's lost property warehouse, alongside some unexpected items, including a bag of cooked frogs and an urn of ashes.

"We didn't keep them," Transport for London manager Diana Quaye said of the frogs.

A sandwich left on London Underground's Victoria line, or a chocolate bar on the top deck of the Number 37 bus, gets chucked away with the frogs and all other perishable items. But everything else is sorted, logged, labelled and filed away in Transport for London's east London warehouse.

BIGGEST LOST PROPERTY OFFICE IN EUROPE

Slightly smaller than a football pitch, the warehouse, packed full of rows of sliding shelves, is the biggest lost property office in Europe and has a staff of 45, Transport for London says.

Umbrella handles protrude from one shelf, books overflow from another, while hundreds of stuffed children's toys, including a huge St Bernard dog teddy and a Rudolph the red-nosed reindeer, sit forlornly, awaiting collection.

One area is dedicated to intriguing finds from over the decades. There's a wedding dress, an artificial limb and a taxidermy fox, amongst other treasures which would delight flea-market enthusiasts.

Under one-fifth of all items lost on London's tubes, overground trains, buses and black cabs are ever reclaimed. After typically holding items for three months, Transport for London decides whether to auction them or send them to charity.

They give sports equipment to a local school, while new toys are given to a children's charity at Christmas.

The urn of ashes, held in a bag that was then stolen, was kept by Transport for London for seven years before eventually being returned to its owner in Germany.

Commuters on buses are the biggest culprits when it comes to lost property, Quaye said.

"I don't know if people get a bit relaxed on the bus, but they tend to leave items on there," she said.