TOMB raiders have allegedly dug up a Roman lead coffin at a Colchester building site and sold it at auction.

The decorative coffin was discovered more than a decade ago by Colchester Archaeological Trust during an excavation in Napier Road.

Archaeologists decided to leave it where it was as it was only partially disturbed.

They were shocked to discover this summer a Roman lead coffin, described as being found in Colchester in 2004, was up for sale at auction.

Previous Roman lead coffins sold at auction have gone for as much as £40,000.

Philip Crummy, of Colchester Archaeological Trust, said: “The information was it was discovered in 2004 and was from the urban garrison investigation site.

“All we know is we haven’t found a lot of Roman lead coffins, there are maybe around 15. And the last one was in 2004.

“I think it probably is this coffin, but we can’t be certain.

“One of the reasons I think it is the one we saw is it looks like what was being sold was intact.”

The trust was carrying out digs before building was allowed to get under way at the former Colchester Garrison site.

After finding the coffin, instructions were left for it to be covered up and left in the ground.

Taylor Wimpey, which developed the site, said it had no knowledge of the coffin being removed. The coffin is of particular historical interest because of what it was made of.

Most Roman citizens were buried in wooden coffins, with only important and rich people buried in lead, making the Colchester coffin rare.

Whoever stole it would have needed machinery as the lead coffin would have been very heavy and easily damaged. Mr Crummy said: “If they were digging without knowing what was there then a machine would rip the coffin. The fact it was complete means it was careful digging.”

Some have been found to weigh up to half a tonne.

Mr Crummy said the coffin belonged in a museum now it us been unearthed. He said: “It’s an interesting lesson to learn and maybe if we had known better we would have dug it up. But we didn’t want to disturb it.”

Historic England, which looks into heritage crimes, is investigating.

Andrew Phillips, Colchester historian, said: “Whoever has done this is a crook. They are known as nighthawks.

“In this area it is pretty rare but clearly this is sadly happening.”