Catholic nuns in Texas have banned their bishop from their monastery for “spiritual safety” in the latest chapter of a remarkable religious spat.

The Discalced Carmelite Nuns of Arlington said they “no longer recognize the authority” of the embattled Bishop Michael Olson, said the Daily Beast, the “latest twist” in a saga that began when he accused a nun of violating her vow of chastity.

Rev Mother Superior Teresa Agnes Gerlach, 43, was dismissed in June following a six-week investigation into claims she had sexual relations with a priest from Montana. Gerlach, who uses a wheelchair and is fed via a tube, was reported to the bishop after allegedly confessing to the affair.

Olson seized Gerlach’s phone, computer, and iPad and claimed the alleged relationship had involved “sexting”. He found her “guilty of having violated the sixth commandment of the Decalogue and her vow of chastity with a priest from outside the Diocese of Fort Worth”.

The nuns have brought a $1 million civil lawsuit against Olson, claiming they have been defamed and intimidated. Explaining their ban, they denied the claims about their Mother Prioress and said they had been “subjected to unprecedented interference, intimidation, aggression, private and public humiliation and spiritual manipulation” by Olson.

Responding, Olson released a statement saying that Gerlach may be excommunicated “by her own schismatic actions,” noted The Telegraph. He added, “This has hurt me as a friend and as the bishop because of the deep wound this has cut in our unity as the Diocese of Fort Worth”.

The Catholic Diocese of Fort Worth told the Fort Worth Star-Telegram that it was aware of the “dangerously rebellious decision” by the nuns and it called for prayers to stop the “open disobedience”.

The spectacular saga has “even reached the ears of senior Catholic figures in the Vatican”, said Sky News. At the end of May, the Vatican appointed Olson as the Pope’s representative and gave him “full governing powers” over the priory. But another senior Catholic, Archbishop Carlo Maria Vigano, has praised the “courageous resistance” of the Texas nuns.