NEW YORK (CNNMoney) -- A federal judge in California ruled that Abercrombie & Fitch violated the law in firing a Muslim employee for refusing to take off her religious head scarf at work.

The lawsuit, originally filed in 2011, accused the popular teen clothing retailer of discriminating against Umme-Hani Khan.

Abercrombie fired Khan, then 19, from a store in San Mateo "for refusing to take off the hijab that her religious beliefs compelled her to wear," the U.S. Equal Employment Opportunity Commission said in a press release.

The U.S. EEOC, a plaintiff in the case along with the former employee Khan, said the ruling by U.S. district judge Yvonne Gonzalez Rogers in San Francisco on Monday is the third ruling against the store Abercrombie & Fitch "involving Muslim employees or applicants wearing hijabs."

The judge said, in court documents, that store managers initially allowed Khan to wear her head scarf, or hijab, so long as it was in accordance with the store's color code. But after she worked there for several months, a district manager visited the store and asked her to take off the hijab while at work.

Khan refused, on the basis of her religious beliefs, so she was suspended. The manager asked her a second time to remove the head covering, and she refused again and was eventually fired, said the judge. "Khan's refusal to remove her hijab was the sole reason for her suspension and termination," reads the court document.

Abercrombie denied the allegations in a prepared statement to CNNMoney: "Abercrombie & Fitch does not discriminate based on religion and we grant religious accommodations when reasonable."

Abercrombie & Fitch has an employee dress code called a "look policy" that forbids head coverings. But it also has a section of its web site called "diversity & inclusion," which includes a quote from Chief Executive Mike Jeffries: "We are determined to have a diverse culture, throughout our organization, that benefits from the perspective of each individual,"

The EEOC said federal judges have found Abercrombie liable in two other discrimination cases, for refusing to hire hijab-wearing job applicants in Northern California and Tulsa, Okla.