Her voice and style, as well as her considerable musical curiosity, prompted opera houses and recording companies to exhume rarities for the Spanish soprano on a regular basis.
Mr del Moral said Caballe's family requested the cause of death not be released while saying she had been in the Barcelona hospital since September.
The star was admitted to hospital because of a gall bladder problem, Spanish media said.
The Spanish opera singer whose song with Freddie Mercury became the featured single of the Barcelona Olympics has passed away.
She began in the Swiss city in 1956, as Mimi in La Bohème, then joined the Bremen Opera, where she sang from 1959 to 1962, in a wide variety of roles.
Lockheed Martin unveils its lunar lander concept vehicle
It would however need to be refueled between missions, potentially using water from the Moon's surface. The NASA's Gateway project provides global lunar access for a Moon lander.
On short notice, Caballe stood in for indisposed American soprano Marilyn Horne in a concert performance in Donizetti's "Lucrezia Borgia" at New York's Carnegie Hall and achieved a thunderous success. She won the school's Gold Medal on graduating in 1954.
She achieved global acclaim in 1965 when she stepped in for another singer in the role of Lucrezia Borgia in Donizetti's opera in NY.
In 2015, at a time when Spain was cracking down on tax evasion as it attempted to rein in a large public deficit during a prolonged economic crisis, Caballe agreed to a fine of 250,000 euros and a symbolic six-month jail term.
Caballe is survived by her husband, Bernabe Marti, an opera singer whom she married in 1964, and their two children Monsterrat Marti and Bernabe Marti Jr.