Archaeologists working on an ancient Roman site in the centre of London are calling on members of the public to share their memories, memorabilia and photographs of the site when it was first excavated 60 years ago.

The Temple of Mithras was discovered on a Saturday afternoon in September 1954, in the last hour of a rather dull and muddy excavation on the site of a dull office block in the heart of the City of London.

In the drab postwar city, its glamour caught the public imagination and it became front-page and cinema documentary news. Police had to be called in to control the crowds, and after the furore over its proposed destruction was discussed at cabinet, the ruins were moved and haphazardly reconstructed on another part of the site.

Now Museum of London Archaeology(MoLA) experts are trying to recover as many memories of the site as possible, and hope to discover colour photographs or even paintings to help with the project to reconstruct it yet again, this time accurately and back on its original foundations.

Site records say the stones were originally joined with pink mortar, but apparently no samples were kept. They hope a visitor may have left with a souvenir piece of mortar in a pocket, and that it’s still out there in a cardboard box on top of a wardrobe.

Already a ticket has turned up that suggests some of the visiting public were allowed to help with the digging. A startling letter, evidently from the friend who secured it for the donor’s aunt, said: “One has to get a ticket from Humphreys of Knightsbridge. We did this and got one for you too because they say today is the last day! So do go along … We found bones and a tooth.”

Sophie Jackson, a MoLA archaeologist, found the ticket and letter fascinating. “Now we’re encouraged to have public engagement in every project, and if possible to involve them in a community dig – but we had no idea they were doing this 60 years ago.”

In 1954 the archaeologists were just clearing up the site before heading off to the pub and leaving it to the developers of an even duller office block when they uncovered the head of a smiling handsome young god, Mithras, looking up from the London clay.

The site was a stroll from the newspaper world of Fleet Street. A press photographer happened to be hanging around, and when his images were released, crowds flocked. By Monday, the imminent destruction of the site had become a political scandal.

Instead the stones were moved, and the temple built in honour of a Persian god particularly revered by Roman soldiers became bizarrely suburbanised, complete with a crazy-paving floor.

Now the site is being redeveloped again, and the temple will be incorporated into a new Bloomberg building. It should be on view to the public again by 2017. The surprise for the archaeologists was how much remained at the original location in Roman times on the banks of the Walbrook stream. They assumed every trace had been bulldozed for the 1954 block, but found extensive foundations and a pickaxe left behind by their predecessors.

Museum of London Archaeology would welcome any memories or images of the site at oralhistory@mola.org.uk or by phone: 020-7410 2266.