The hidden secret of a castle's marble sculptures has been given away by a boy's smile, say experts.
The boy's smile confirmed he could not date from Roman times
A team of top archaeologists found that nine of 11 statues at Powis Castle in Welshpool were not Roman originals but 18th Century copies.
A sculpture of a smiling boy captured the experts' attention when asked to research how old the statues were.
The smile made them suspicious as genuine Roman carvings are sombre and were used as monuments to the dead.
The study by archaeologists, from Oxford, was part of a wider project to replace missing items from the castle's figures, including a spear and a finger. Castle owners' the National Trust said it was one of the largest conservation projects of its type it had undertaken.
STATUE WATCH - HOW TO SPOT THE DIFFERENCE
Are the feet parallel? Roman sculptors placed feet apart at an angle
Is there a knowing smile? 18th Century collectors liked the romantic, smiling face
Does the statue have flowing hair? This was favoured in the 18th Century, not ancient Rome
Does the statue seem to have a mix of styles which makes ageing the statue difficult?
Does the aged look of the statue look suspiciously even?
"We have long suspected their (the statues) true origins," said Margaret Gray, house manager of Powis Castle.
"However, this investigation, which is part of a wider conservation project, has allowed a closer look to reveal the definitive results for the first time."
The results confirmed the exceptional quality of the pieces within Powis Castle, said the National Trust.
One, a statue set upon an altar, is a genuine Roman sculpture of "exceptional detail and quality," dating back to the late 1st Century AD.
Another of a cat crouched over a snake, dating from the 1st or 2nd Century BC, was brought by Lord Clive of India whose collection is stored at the castle.
Another four statues are a combination of fragments of Roman sculpture with some imaginative 18th Century additions, such as longer hair.
Five statues, of a young boy holding a bird and a man in a toga, are important 18th Century works by one of the most renowned sculptors of his time, Cavaceppi.
Andreas Kropp, from the Institute of Archaeology in Oxford, was working for Cliveden Conservation who carried out the research.
He said:"The smiling expression of one boy was peculiar, because the overwhelming majority of Roman figures of children were used as funerary monuments.
"In another piece (a statue of a young boy holding a dove) there is a very strange ensemble of ancient pieces."