One of the largest and most mysterious bronze age hoards ever found in the UK contains objects that have astonished archaeologists, including items more commonly found in France and the Alps.

The Museum of London on Monday revealed new finds among the Havering hoard, a remarkable collection of 453 swords, axes, knives, chisels, sickles, razors, ingots and bracelets excavated from a quarry in east London over a period of three months and revealed last year.

Dating from 900-800BC, it is the third largest bronze age hoard ever discovered in the UK.

Closer examination has revealed what are believed to be a pair of terret rings, used to prevent the reins tangling on horse-drawn carts. Bronze age examples have been found before in France but not the UK.

A bracelet discovered in the Havering hoard unveiled ahead of the Museum of London’s major exhibition at its Docklands outpost. Photograph: David Parry/PA

There is also a bracelet believed to be from what is now north-west France, and copper ingots possibly originating from the Alps.

Kate Sumnall, a curator of archaeology at the museum, said the unexpected finds suggested links to Europe that were nearly 3,000 years old.

“These objects give clues about how this wasn’t an isolated community but rather one that fitted into a much larger cultural group with connections along the Thames Valley and across the continent.”

What the discoveries do not do is help solve the mystery of the hoard’s origins. Sumnall is curating an exhibition on the hoard to be staged at the museum’s Docklands outpost in April, and she admits there are still more questions than answers.

Axe heads and other rare objects discovered among the Havering hoard. Photograph: David Parry/PA

“We pulled together a room full of bronze age specialists to discuss some of this, to discuss our interpretation and hopefully to narrow things down … and you can’t get the room to agree,” she said.

There are four theories about why so many objects would have been deliberately broken and meticulously buried.

Was it a ritualistic offering to the gods?

Was it to do with it being the late bronze age and start of the iron age, so the objects were no longer so highly valued or wanted?

Could a powerful person have been trying to control the amount of bronze that was in circulation and being traded?

Or was the location a kind of bronze age storage site? The total weight of the objects is 45kg, so they could not have been easily carried around.

All of the theories raise their own questions. If they were being stored, for example, why were they not retrieved?

Sumnall said the exhibition would not be prescriptive. “We will be saying: here are the clues, form your own conclusion.”