(With acknowledgement to Barcroft Media)

The discarded pictures, which were retrieved by a caretaker who was looking after a building being turned into flats in 2006, have spent the last five years in a carrier bag underneath his bed.  
The 59-year-old, who wishes to remain anonymous, said that after the occupants of the Westminster office building moved out, the album and a number of documents were thrown into a skip outside.
He said: ‘I took the ledgers to the Tower Bridge Museum because I thought they might have some historical value.

A view of the bridge: The sturdy steel frame of Tower Bridge can be seen, before it was covered with its distinctive stone-cladding on the orders of architect John Wolfe-Barry

‘They included records of the materials and used in the bridge's construction and what they cost.
‘I told the man at the museum that I had also found some photos but he told me they already had plenty of those.
‘I didn't know what to do with them so I wrapped them in some brown paper and put them in a bag under the bed.’ It wasn't until earlier this month, when the owner of the photos mentioned them to his neighbour, City of Westminster tour guide Peter Berthoud that the significance of the find fully emerged.
Mr Berthoud, an expert in the history of London who gives guided tours around famous landmarks including Tower Bridge , said he was gobsmacked by the haul.