An Alabama Catholic school principal nearly doubled enrollment in two years by recruiting Hispanic students, but was fired when she took a stand against discrimination toward Hispanics by a staff member, she alleges in a federal lawsuit filed Feb. 10.

Bishop Robert J. Baker, head of the Catholic Diocese of Birmingham, said he was previously unaware of the allegations in the lawsuit, but he is looking into them. He said he couldn't comment further at this time.

"Maria Nolen was not terminated for the reasons she alleges in her complaint or for any other discriminatory reason," said John Whitaker, an attorney for the diocese. "We are an inclusive religion and thus would not exclude anyone for reasons related to their race. Hispanics are as welcome in our churches and schools as any other race."

Maria Nolen said in the lawsuit filed in U.S. District Court that when she was hired as principal of St. Ann Catholic School in Decatur in July 2012, the school was in financial turmoil with a declining enrollment of 54 families.

By October 2014, she had increased enrollment to 90 families by actively recruiting Hispanics, she said. She raised more than $176,000 from Student Scholarship organizations to pay for scholarships for need-based assistance for underprivileged students to pay their tuition, the lawsuit states.

Nolen had repeated confrontations with her secretary, the wife of an advisory board member and financial advisor to the diocese, when the secretary refused to take part in programs to help Hispanic students and made derogatory remarks about them, saying, "Can you believe how stupid Mrs. Nolen is to think I am going to give up my Saturday to help these people?" the lawsuit alleges.

The secretary made repeated derogatory remarks about Hispanic students, families and scholarship applicants and put a sign with written instructions on doors and said, "if they could speak English and read it, this would help," the lawsuit alleges.

The director of human resources for the Diocese of Birmingham instructed Nolen to stop reprimanding her secretary, the lawsuit alleges. Nolen refused and again reprimanded the secretary on Oct. 24, 2014. The secretary resigned.

The next month, Nolen was criticized at an advisory board meeting for accepting under-qualified Hispanic students, the lawsuit alleges. She said that all applicants had to pass an entrance test and all the Hispanic students had passed.

On Dec. 12, 2014, Nolen was accused by her supervisor of embezzlement and her resignation was demanded, the lawsuit says. Nolen asserts in the lawsuit that she has never stolen school funds and kept accurate records of purchases of school supplies. The lawsuit said she was given no opportunity to respond to the accusations and she was subjected to involuntary termination as retaliation because she opposed the discrimination against Hispanics by the school and diocese. She alleges that her secretary's spouse used his position on the advisory board to retaliate against her opposition to the secretary's discriminatory actions.

The lawsuit asks for back pay, punitive and compensatory damages and attorney's fees.

AL.com writer Kent Faulk contributed to this report.