BEIJING -- A secretly appointed Roman Catholic bishop detained by China for the past 14 years due to its feud over authority with the Vatican has died at age 94, a Roman Catholic website said Friday.

Chinese officials informed the family of Bishop Cosmas Shi Enxiang on Jan. 30 that he had died, but didn't say when or provide his relatives a cause of death, ucanews.com reported.

Shi was ordained in 1947, two years before officially atheistic China was founded. Shortly afterward, Chinese leader Mao Zedong demanded Chinese Catholics sever their links with the Vatican, churches were closed and, like scores of priests, Shi suffered long terms of imprisonment and hard labour between 1957 and 1980.

The Vatican secretly appointed Shi as bishop of the northern city of Yixian in 1982, but he was taken away again in 2001 and held at an undisclosed location.

Beijing now allows Christians to worship openly, but it has no formal relations with the Vatican and insists that the Communist Party-controlled Chinese Catholic Patriotic Association has the authority to appoint bishops rather the Holy See.

China has an estimated 12 million Catholics many of whom worship outside the official Patriotic Association.

Even after churches were permitted to reopen, Beijing continued to harass and detain so-called underground priests such as Shi who remained fervent in their loyalty to the Pope.

Ucanews.com said that with Shi's death, Bishop James Su Zhimin of Baoding is the only remaining underground bishop still being held in secret detention.

However, Shanghai's bishop, Thaddeus Ma Daqin, has not been seen in public for years and is believed to be confined to Shanghai's Sheshan Seminary. He was taken there hours after his 2012 ordination, during which he publicly renounced membership in the Patriotic Association, shocking and angering officials.