An outspoken former Philippine diplomat, seeking asylum in the United States charged in federal court here yesterday that the Marcos government was ready to hire a Mafia figure to harm his family if they refused to return voluntarily to the Philippines.

Documents filed in District Court by the former diplomat, Joselito C. Azurin, include what is alleged to be a text of a July 12 cable from the Philippine foreign ministry to its Washington embassy. The alleged cable, partly in English and partly in the Philippine language, Tagalog, authorized the embassy to arrange with a "Mafia man" to injure Azurin's wife or youngest child.

It was not possible late yesterday to determine whether the cable was authentic. James H. Lesar, one of Azurin's lawyers, declined to say how he had obtained either the text of the cable or any of the 11 other internal Philippine government documents, some marked "Confidential," that were filed in court yesterday. Lesar said, furthermore, that he did not know the "ultimate source" of the documents.

But he added, "We reported the threat [against Azurin's family] to the State Department and have met with the FBI about this."

A State Department spokesman declined to comment on any aspect of Azurin's battle for U.S. asylum. An official of the U.S. Attorney's office here said that prosecutors had not yet had time to review the newly filed documents and could not comment on them. No comment could be obtained from the Philippine embassy.

In his court petition yesterday, Azurin asked the State and Justice departments, however, "to admit . . . the truth" of a series of assertions, including the authenticity of the July 12 cable that mentioned his family.

Azurin, a former charge d'affaires of the Philippine Embassy in Australia, is currently the center of a complex legal battle that has rallied consiredable support for him among Filipino dissidents in Washington.

The Australian government is seeking to extradite Azurin for prosecution on embezzlement charges. Azurin contends, however, that the Australian government plans to deport him to the Philippines, where he will, he asserts, be punished because of his criticism of President Ferdin and Marcos' regime. The Philippine government has termed Azurin's statements "preposterous."

The alleged July 12 cable, marked "encode," purports to relay from Manila to the Philippine embassy in Washington the orders of a key Philippine general, Fabian C. Ver, who heads the Marcos government's intelligence and security agency.

His alleged instructions say: "Make ways under strictly discreet and diplomatic manner-- repeat, strictly discreet and diplomatic manner-- [to] convince Azurin family [to] return rp [to the Republic of the Philippines], amnesty awaiting."

Then the cable adds: "If embassy deems it necessary, make arrangements with Mafia man [kung kinakailangan masaktan] preferably youngest Azurin child if not wife.' The Tagalog words "Kung Kinakailanganmasktan" were translated by Azurin's lawyer and several neutral Tagalog-speaking persons yesterday as meaning to "harm, injure or inflict pain if necessary."

According to his lawyer, Azurin's wife, Norma, 37, and five children currently live in McLean.His youngest child is a daughter, Jane who is 6 year old. Azurin has been imprisoned since April, for the most part at the Arlington County jail.

Azurin's court allegations yesterday were the latest development in an extradition battle that will likely continue for a considerable time. The alleged July 12 cable and other documents filed in court yesterday appeared designed to bolster Azurin's contention that his extradition would be in tended as punishment for his political views rather than a criminal act.

The former diplomat's fight to gain asylum in the United States received an initial setback in June when Judge Oren R. Lewis ruled in U.S. District Court in Alexandria that Azurin may be extradicted to Australia for prosecution on the embezzlement charge.

Shortly afterward, however, Azurin petitioned the U.S. District Court here for a writ of habeas corpus, arguing that his extradition would be illegal and that his current imprisonment violates U.S. laws, the American Constitution and treaties between the U.S. and Australia. He has asked the court to order his release from jail.

Officials of the U.S. attorney's office here, who act as representatives of the Australian government in such legal proceedings, urged the court yesterday to reject Azurin's claims. They argued, in part, that the District Court in the District of Columbia lacks jurisdiction in the case because Azurin is in custody in Virinia.

If Azurin's court efforts fail, a final decision on whether he will be extradited would be made by Secretary of State Cyrus Vance, Vance has not indicated his views on the issue. According to Justice Department officials, Vance must reach his decision within two months after legal proceedings end. The Secretary of State, officials say, is permitted to reject court findings and make his determination on political or humanitarian grounds.

Azurin has been charged by Australian authorities with embezzling more than $81,000. He was accused of cashing an Australian check, payable to the Philippine government, and then flying to San Francisco with the money.

Azurin has argued that the charge was trumped by the Marcos regime. He has described the alleged transaction as part of a kickback scheme arranged by other Philippine officials. Some of the documents filed by Azurin in court yesterday-- including alleged lists of the contents of diplomatic pouches carried between Manila and the United States-- appear designed to help corroborate this contention.