Italian opera superstar Luciano Pavarotti is in hospital in northern Italy after being admitted on Tuesday.
Pavarotti, who was diagnosed with cancer last year, was taken to the Policlinico hospital in his hometown of Modena for medical checks, a spokesman said.
He could not confirm a newspaper report that the singer, who underwent an operation to remove a pancreatic tumour in July last year, was suffering from pneumonia.
The cancer operation forced Pavarotti, regarded by many as the greatest tenor of his generation, to cancel his 2006 farewell opera tour. The 71-year old singer has not been seen in public since, prompting media speculation about his health.
Since his operatic debut in 1961, the tenor has become one of the most recognised classical musicians in the world, regularly gracing the stage at New York's Metropolitan Opera, London's Covent Garden and Milan's La Scala.
His fame grew when he sang Puccini's aria "Nessun Dorma" at the soccer World Cup in Italy in 1990 alongside Placido Domingo and Jose Carreras.
Pavarotti's London-based manager, Terri Robson, last month denied his condition had worsened, saying he was working on a recording of sacred songs and teaching a group of students daily.