MANILA -- Sr. Mary Rosario "Chayong" B. Battung, the inspiration behind the 1984 highly political film "Sister Stella L," played by Vilma Santos, peacefully passed away on November 25 in Quezon City. She was 78.

The sad news was confirmed by Religious of the Good Shepherd in a Facebook post on Thursday.

"Sr. Chayong is from Tuguegarao, Cagayan. After years of exposure to the various social ministries of the congregation, she entered the novitiate in Christchurch, New Zealand. Throughout her ministries, she has always preferred to be among the urban and rural poor, the neglected, and with those who have been deprived of their basic human rights. While Sr. Chayong worked with labor unions in Cavite, she also reached out to the urban poor in Tondo. In popular culture, the 1984 film 'Sr. Stella L.' was based on her life but she herself would say the film is about activist nuns in general. She was also active in fostering the understanding and development of feminism in the Philippines. Later, she would immerse herself in the development of 'hingalangin', a form of prayer that is centered on Filipino understanding of mindfulness," the post read.

"She is survived by her biological sister, Sr. Angela B. Battung, RGS. Thank you for the zealous offering of yourself, Sr. Chayong. Pray for us and continue to intercede for more women to offer themselves generously to the mission," it added.

A private wake will be held at the Good Shepherd Convent in Quezon City. The Mass of the Resurrection is scheduled on November 28 at 10 a.m. The inurnment will follow at the Good Shepherd Columbary.

Written by Jose Lacaba and directed by Mike de Leon, "Sister Stella L" is a film about a nun who becomes a crusader for wronged laborers.

In a previous interview, Santos said she was not aware yet of political issues when she made "Sister Stella L," which was shown during the latter part of the Marcos regime.

“Hindi ko pa naiintindihan ang sitwasyon noon. All I had to do was act,” Santos said at the time.

“But now I am aware of the conditions already. Relevant ang ‘Sister Stella L.’ because it still speaks until now of the current situation in our society. Pareho pa rin ang nangyayari at pareho pa rin ang nakikita natin sa ating paligid,” the screen veteran added.