When John Barratt drilled a hole into an old vase and turned into an electric lamp, he had no idea he was messing with a 2,000-year-old relic worth more than a third of a million pounds.

He fitted a lamp socket and furnished the 19-inch urn with a red lamp shade.

Nearly 40 years later, despite his alterations, it sold for £370,000 at Christie's auction house on Friday.

Mr Barratt, a retired school teacher who died last year, had inherited the urn and kept it at his Bath home....