Italian art police on Friday revealed they have recovered two ''priceless'' Roman statues of key imperial figures in the latest of a series of operations to crack down on antiques trafficking.

They described a marble head of Emperor Lucius Verus (130-169 AD) and a bust of his adoptive mother Faustina the Elder (105-140 AD) as ''of a beauty and scientific importance equal only to a few other pieces'' in the Louvres and the British Museum.

The head of Verus, who ruled the empire alongside his adoptive brother Marcus Aurelius for eight years, was discovered hidden in a boathouse used by a Rome art dealer at the coastal town of Fiumicino. An adopted son of both Emperor Hadrian and his successor Antoninus Pius, Verus is shown with a mass of curly hair and a long beard that he reportedly used to sprinkle gold dust into to highlight its blond colour.

Police tracked down the bust of Faustina the Elder to the US, where it ended up after being stolen from the Roman theatre of Minturno in Lazio in 1961 and bought by an American collector in the 1980s.

A temple to Faustina and her husband Antoninus Pius still stands in the Roman Forum, where it was built by the grief-stricken Antoninus Pius when she died and later rededicated to them both by their adopted son Marcus Aurelius.

Twelve other important artefacts have been recovered as part of the same operation, with a series of Greek vases and a haul from an ancient Etruscan grave found hidden alongside Verus's head in the boathouse.

All the works will go on show in Rome later this month at Castel Sant'Angelo for an annual exhibition of artefacts recovered by art police that runs from April 24 to June 19.