Artefacts recently unearthed in the Netherlands seemed to show that Christianity was openly practised there much earlier than previously thought. But now they have been shown to be fakes.

The archaeologists who dug up the pieces admitted their error last week in the 2005 yearbook of the historical association Numaga. The artefacts, including four pieces of pottery and glass, and a lead platter, were found at different sites in Nijmegen, the oldest city in the Netherlands, between 1995 and 1999. They were briefly displayed five years ago at Nijmegen's Valkhof Museum.

Most historians think that Christianity was first practised openly after AD 400. But the team of archaeologists, led by Harry van Enckevort, at first dated the items at about AD 200. Other archaeologists expressed doubts about the objects' authenticity at the time of the finds, but it was not until last year that van Enckevort decided to have the finds scientifically analysed.

The tests showed that the inscriptions on the glass and pottery shards were added in the 1990s, although the shards themselves were from around AD 200. The lead plate was a mere 20 years old.

“You don't expect objects to be fake when you find them embedded in the ground,” says van Enckevort. Their appearance had convinced him that they were genuine.

The Dutch scandal is the latest of several recent archaeological scams. Earlier this year staff at the Israel Museum in Jerusalem had to remove from display one of its most prized pieces — an ivory pomegranate that bears an inscription hinting that it had been used by priests in Solomon's Temple — after finding out that it was fake (see Nature 434, 13; 2005). And in 2000 one of the most famous archaeologists in Japan, Fujimura Shinichi, was caught burying artefacts at an archaeological site.

Lothar Bakker, director of the Roman Museum in Augsburg, Germany, and an expert in Christian inscriptions on Roman objects, says that he “wouldn't have trusted the objects” because similar finds have always been later than AD 400.