San Francisco, July 20 (AP) Legal minds were attuned sharply today to a case in federal court here questioning the right of the government to intern American citizens of Japanese ancestry.

The action to test the constitutional civil rights of such persons when such rights apparently are in conflict with wartime military orders was before Federal Judge Michael J. Roche.

It was brought by Miss Mitsuye Endo, 22, former state civil service employee at Sacramento. She now is interned at the Tulelake reception center. In resisting internment her complaint declared her rights as an American citizen were violated in that she was being held under armed guard while no law violation was charged.

James C. Purcell, her attorney, told Judge Roche, "so far as I know there never has been a decision of the supreme court of the United States upholding the right of a military commander to hold a citizen of the United States without hearing."

Members of the staff of the army's judge advocate sat in on the hearing, as did a deputy from the state attorney-general office, and an attorney of the Civil Liberties Union. The government's case was being directed by Assistant U.S. Attorney A. J. Zirpoli.

The case is being heard by Judge Roche, without a jury."