Montserrat Caballé, the feted Spanish soprano who won a new generation of fans after singing Barcelona with Freddie Mercury, has died at the age of 85.

A spokesman for Barcelona’s St Pau hospital, Abraham del Moral, confirmed her death early on Saturday. The singer had a stroke in 2012 and had been admitted last month for a gall bladder problem, according to Spanish media reports.

Caballé was born into a working class family in Barcelona. Her musical talents became apparent early on – she was singing Bach cantatas at the age of seven.

The singer achieved international acclaim in 1965 when she stepped in for another performer in the notoriously difficult role of Lucrezia Borgia in Donizetti’s opera in New York. Her debut went down in opera history as one of the greatest overnight successes and she went on to tour the world in a career that spanned half a century, starring in 90 opera roles and giving almost 4,000 performances.

The Guardian’s Martin Kettle once described Caballé as “the finest bel canto soprano of the post-[Maria] Callas age. For those who prize sheer beauty of sound and true legato singing, she has no peer since Rosa Ponselle in the 1920s.”

In 2004 she was placed sixth in a BBC Music Magazine list of the top 20 sopranos of the recorded era, as voted by opera critics, after Callas, Joan Sutherland, Victoria de los Angeles, Leontyne Price and Birgit Nilsson.

The semi-operatic Barcelona was first released in 1987 and featured at the Olympic Games in 1992, the year after Mercury died. It initially reached no 8 on the UK singles chart, making it one of the Queen singer’s biggest solo hits, before peaking at no 2 on its re-release to coincide with the Olympics.

In December 2015, Caballé was given a six-month suspended jail term and fined more than €250,000 (£180,000) for tax evasion.

She was placed under investigation in 2014, accused of channelling earnings through a company in Andorra when she lived in Barcelona and thus defrauding tax authorities of €500,000, which she subsequently paid.