LOS ANGELES — An ugly legal battle between one of world's most popular artists and a group of nuns over a real estate deed turned tragic when one of the sisters involved died in court Friday. CBS Los Angeles reports that Sister Catherine Rose was one of the nuns fighting Katy Perry over the singer's claims to the Los Feliz property on which a former convent of the Los Angeles Archdiocese once stood.

She collapsed during a court hearing in Los Angeles Friday, in what has been a protracted effort by the nuns to keep Perry from taking ownership of the property.

On the nuns' website Stand With The Sisters, the message "Rest with the angels our most precious treasure" is seen above a photo of Sister Catherine Rose.

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Late Friday, Los Angeles Archbishop Jose Gomez issued a statement that read in part: "Sister Catherine Rose Holzman, IHM passed away suddenly at the age of 89.[…] Sister Catherine Rose served the Church with dedication and love for many years and today we remember her life with gratitude.[…]"

In dispute is the sprawling property in Los Feliz Sister Rose and her fellow nuns bought back in the 1970s from philanthropist Daniel Donohue. The nuns wanted to sell the convent to restaurateur Dana Hollister.

A judge ruled in 2016 that the nuns' sale to Hollister was invalid, paving the way to a purchase by Perry from the Archdiocese of Los Angeles.

Hollister was ordered to pay Perry $5 million in punitive damages for interfering with the sale.

The nuns left the property in 2011.

It's not clear if or when Perry plans to move into the property.

In 2015, CBS News correspondent John Blackstone reported that Perry, who started her career singing Christian music, even met with the sisters to make her case. She sang a gospel song for them, but they weren't impressed.