ROME (Reuters) - Historians and scientists have exhumed the remains of legendary castrato Farinelli in Italy to study the anatomical effects of castration carried out on young boys to turn them into high-pitched stars of the opera.

Castrati played heroic male leads in Italian opera from the mid-17th to late 18th century when the bel canto was the rage in Europe. Farinelli, born Carlo Broschi in 1705, was the most famous of them all, in a stage career lasting from 1720 to 1737.

Carlo Vitale of the Farinelli Study Center in Bologna said they had recovered the bodies on Wednesday of the singer and his great-niece, who moved his body from a first grave destroyed in the Napoleonic wars.

His final resting place in Bologna's Certosa cemetery was only recently discovered.

"They are in a middling state of preservation but the scientists say there is something to work on," Vitale told Reuters from the graveyard, where Farinelli and his great-niece lay beneath a tombstone with a long Latin epitaph.

His remains were to be taken to Bologna University for study by a team of scientists including an accoustics expert eager to find remains of the vocal chords and larynx to discover what gave castrati such extraordinary vocal range and power.

"This is the only skeleton of them we have," said Nicholas Clapton, a British expert on the castrati.

"We want to know if they were like the cartoons at the time depicted them, tall and dangly, or with women's breasts and large buttocks, or like the grand gentleman in Farinelli's official portraits," he told Reuters.

A singing professor at the Royal Academy of Music in London and curator of an exhibition on the composer Handel's use of the castrati, Clapton said the removal of boy chorists' testicles kept their vocal chords small while the hormonal changes meant their bodies kept growing well into adulthood.

"That gave them huge lung capacity but with a very sweet voice," he said.

It could also mean castrati grew abnormally tall or fat and could sprout breasts, though surviving official portraits of Farinelli depict a handsome man in fine dress.

Castrati also had their critics who thought their voices were ghastly and their mutilation was barbaric.

The Catholic Church banned it on pain of excommunication, while also using castrati in choirs and the Vatican's Sistine Chapel until as recently as 1903, Clapton said.

The last surviving castrato, Sistine Chapel chorist Alessandro Moreschi, lived long enough to make recordings in 1902 and 1904, though on the dated gramophone records his voice sound like what Clapton described as "Pavarotti on helium".