Museums in England could soon run out of space for historic artefacts, according to a new report commissioned by Historic England and Arts Council England.
The report shows that unless more storage space is acquired, the number of new finds will soon be greater than the space available to store them.
Barney Sloane, national specialist services director at Historic England, said: "The clock is ticking – we have four or five years before we really do start seeing massive problems."
Many new finds come via archaeological contractors hired by developers before clearing sites for construction.
London's largest mosaic find in 50 years, for example, was discovered during a regeneration project near the Shard.
Historic England, along with Arts Council England and National Trust, are in early talks to advise government on the creation of a national archive to address the problem.
They say this could solve the issue of storage for the next 100 years. If, that is, government commits to funding it.
"The potential of archaeological archives is really rich," said Sloane. "It would be a massive shame if we couldn't find a way of making sure they are protected for the future."