A federal judge in Alexandria has held the daughter and son-in-law of deposed Philippine president Ferdinand E. Marcos in contempt of court and ordered them to jail for refusing to testify before a grand jury investigating U.S. arms contracts with the Philippines.

The contempt citation, imposed Tuesday by U.S. District Judge Claude M. Hilton during a closed hearing, was revealed by the former president and his wife Imelda Thursday night when they spoke by telephone from Hawaii with supporters in Los Angeles.

" . . . Promises that our family would be given hospitality and be treated fairly are being violated," the former president told the gathering.

Marcos and his wife said that execution of their daughter's sentence was delayed for 30 days.

"She has been accused of contempt of court because she did not know anything," The Associated Press quoted Imelda Marcos as saying. "What does she know about arms sales?"

Justice Department officials and U.S. prosecutors in Alexandria declined to comment.

Other sources said the couple, Irene and Gregorio Araneta, who have been staying in Hawaii with the Marcoses, were told to report to Alexandria June 20 to begin serving their sentences, the length of which could not be learned yesterday.

They are expected to appeal. Hilton permitted the couple to return to Hawaii, the sources said.

The Aranetas arrived at the Alexandria federal courthouse Tuesday morning and appeared before Hilton in a 50-minute closed hearing in the afternoon.

It is not known why government prosecutors are seeking testimony from Irene, one of Marcos' three children. State Department sources said that prosecutors in Alexandria have been "very aggressive" and speculated that they are "casting as wide a net as possible."

Since late 1984, the Alexandria grand jury has been investigating alleged fraud and possible kickbacks to Philippine officials in connection with military contracts totaling more than $100 million and partly financed under the Pentagon's foreign military sales and credits program.

Investigators are also interested in reports of the illegal resale to other countries of U.S.-purchased military items, a source said.

In March, Gen. Fabian Ver, former military chief of staff in the Philippines, and Eduardo M. Cojuangco, a millionaire buinessman and close associate of Marcos, appeared briefly before the grand jury. Sources said they refused to answer questions and are expected to be subpoenaed again.

State Department officials said yesterday that Marcos sent a telegram early this week protesting a subpoena served on his 25-year-old daughter.

Assistant U.S. Attorney Ted Greenberg, Justice Department attorney Peter Clark, a specialist in the Foreign Corrupt Practices Act, and Victoria Toensing, a deputy assistant attorney general in the criminal division, are expected to visit the Philippines soon. They are to pursue evidence of possible criminal wrongdoing by U.S. corporations during Marcos' reign, according to department officials and other sources.

On Thursday Dr. Eduardo Guiyab, a Long Island dentist, was given immunity and testified before the panel for half an hour, according to sources.

Guiyab's wife Maria, a psychiatrist, and his brother Lupo, a medical intern, also were subpoenaed, but told to return in July.

The Guiyabs are brothers of Edna Camcam, a woman described as a close friend of Ver. Camcam was subpoenaed but failed to appear this week.

Investigators are seeking to question her about funds connected with the U.S.-financed military contracts, sources said.

Benjamin Romualdez, former Philippine ambassador to the United States and brother of Imelda Marcos, also has been asked to appear before the grand jury, sources said.