The Justice Department asked a federal judge yesterday to appoint a psychiatrist and physician to determine the accuracy of former Rep. Otto E. Passman's claim that he is too ill to stand trial on charges of receiving bribes from Korean businessman Tongsun Park.

Justice Department attorney Jeffrey E. White said the independent examination was required because Passman, a Louisiana Democrat, "does not seem to be suffering from any substantial physical ailment other than that associated with advancing age."

The 77-year-old Passman has been hospitalized in a psychiatric ward of a New Orleans hospital since March 29 - two dats before he was indicted here on charges of receiving the $213,000 from Park in the Korean influence-buying scandal.

Passman was scheduled to be arraigned last Friday in federal court here, but his attorney asked for an indefinite postponement of that appearance on the basis of a letter from a psychiatrist who said Passman is suffering from "significant depression" and is being treated with drugs for the illness.

However, the government quoted another doctor, Dr. Gene Usdin of New Orleans, who said Passman is suffering from "an early senile dementia" and "agitated depression" and is not too ill to show up in court.

"Dr. Usdin believes that Mr. Passman's depression is occasioned by his involvement in the instant case, his reelection defeat, and possibly his wife's illness," White said in court papers filed yesterday.

Usdin said in a letter filled in court yesterday that an indefinite postponement of Passman's court appearance was unnecessary, but that about three weeks would be long enough to predict the effectiveness of Passman's drug treatment for depression.

White said the government believes the independently appointed doctors could report on their examinations of Passman by May 5.