WASHINGTON (AP) _ Two Americans with a hidden tape recorder and phony credentials as arms procurers tricked former Philippine President Ferdinand E. Marcos into revealing a plan to invade his homeland, and then gave the information to the Philippine government, the Americans testified Thursday.

Their statements - and tapes of their conversations with Marcos at his Honolulu home earlier this year - also indicated that Marcos claimed to have up to 1,000 tons of gold hidden in a secret cache and $500 million in Swiss bank accounts.

The bizarre revelations were made by two Virginia Beach, Va., men, Robert Chastain, a business consultant, and Richard Hirschfeld, an attorney, at a hearing of the House Foreign Affairs subcommittee on Asian and Pacific Affairs.

Chastain testified that he made the tapes and turned them over because ″it was wrong to allow President Marcos to proceed on his path to armed invasion as if no one knew what he intended to do.″

It was, according to committee member Chester Atkins, D-Mass., ″a shabby, sordid tale of gold bullion being offered for weapons to overthrow an ally of the United States.″

In Hawaii, Marcos spokesman Arturo Aruiza said Marcos will not comment until he can talk to his attorneys.

According to the testimony and the tapes, Hirschfeld and Chastain worked their way into Marcos’ confidence, beginning in September 1986, on the strength of their business association with Mohamed al-Fassi, a businessman with contacts with the Saudi Arabian royal family.

Hirschfeld had already been in the public eye as a business associate of former boxer Muhammad Ali and as the subject of Securities and Exchange Commission investigations of wrongdoing in connection with stock offers.

Hirschfeld and Chastain convinced Marcos they and al-Fassi were willing to help get arms and money for an invasion of the Philippines that was originally set for late June and eventually was planned to take place this Friday, Hirschfeld testified.

Speaking to Chastain, who had hidden a voice-activated recorder in his briefcase, Marcos said during a meeting on May 21 he wanted anti-tank weapons, anti-aircraft missiles, rifles, mortars and enough ammunition for a three- month fight, the committee was told.

Marcos was to land by boat in his home province Ilocos Norte, where he would be greeted by supporters and swept back to control of the Philippines.

″I am going to land there, I don’t care who opposes me,″ Marcos said, according to the tapes. ″And if they oppose the landing, that is when we start the battle.″

What was to happen to the current president of the Philippines, Corazon Aquino, who took office after Marcos was swept aside by a popular revolt in February 1986?

″What I would like to see happen is we take her hostage,″ Marcos told Chastain. ″Not to hurt her ... no reason to hurt her .. to take her.″

According to the tapes, which were played to a packed committee chamber, Marcos planned to pay for the invasion with a line of credit extended by al- Fassi. In return Marcos said he would give the Saudi a lien on his Swiss holdings.

In addition, Marcos told Hirschfeld that he owned 1,000 tons of gold, worth $14 billion, that was hidden, perhaps in the Philippines. Marcos was vague about where he had obtained so much gold, except to indicate that some of it may have come from money set aside to pay Philippine veterans after World War II and some of it may have come from the Philippines’ central bank.

Marcos also was vague about where the gold was and who knew its location, but was definite that his wife Imelda did not know its whereabouts.

″She panics,″ Marcos told Hirschfeld in a whispery voice he used for all the conversations about the gold.

The lawyer said he was able to record those whispers because the more confidential Marcos tried to be, the closer he leaned to Hirschfeld’s back-up tape recorder in a breast pocket.

Since revelation of the tapes, State and Justice Department officials have restricted Marcos to the island of Oahu, Hawaii, forbidding him to travel anywhere within the United States or outside the country.

According to initial reports of Marcos’ scheme, the tapes were made with the cooperation of the Justice Department.

Chastain and Hirschfeld said, however, that before they made the recordings they tried to get U.S. officials involved - they even notified Vice President Bush’s office, they said - but were unsuccesful.

Bush’s office was contacted because Hirschfeld had met officials there in early 1985 when as Ali’s lawyer and had been briefed on Middle East issues before accompanying the retired boxer on a trip to Lebanon aimed at trying to release U.S. hostages.

Jerris Leonard, a former assistant attorney general now representing Hirschfeld, said he gave the Justice Department lists of weapons sought by Marcos and other evidence of the former president’s activities in an effort to get U.S. officials involved in the caper.

In return, the department advised him and his clients to stop seeing Marcos, he said.

″They tell us, excuse the expression, stick it in your ear, then I guess if you’re concerned citizens as certainly Mr. Chastain and Mr. Hirschfeld are, maybe they do it on their own,″ Leonard said.

Justice Department representatives did not appear at the hearing and the committee did not delve into Chastain and Hirschfeld’s motives for taking it upon themselves for trapping Marcos or ask why the Justice Department declined to deal with them.

Hirschfeld was charged with criminal contempt last year for allegedly violating an SEC order to stop selling stock in Champion Sports Management, a company with which Ali was associated.

In 1974, the SEC complained about a stock offering by a bank Hirschfeld led.

On June 4 he contacted the Philippine government, through its U.S. attorney and eventually gave them the tapes. The Philippines’ authorities passed them to U.S. officials.

For his part in the affair, al-Fassi was made an honorary consul-general of the Philippine government, Hirschfeld said.

President Reagan invited Marcos to come to the United States in late February 1986, for the most part to get him out of Philippine politics after 20 years of rule that had deteriorated amid charges of corruption, human rights abuse and inefficiency in fighting a communist insurgency.

There has been periodic evidence since then, however, of Marcos’ efforts to regain power in his country, but not as dramatic as that offered on Thursday.

None of the participants in the taping of Marcos, nor State Department officials who tesfied later, said there was firm evidence that Marcos actually had the capability to mount an invasion or that the gold he claimed to have actually existed.

Gerald Lambertson, a deputy assistant secretary of State for East Asian affairs, said, however, that Marcos loyalists have engaged in sabotage, disinformation campaigns and perhaps terrorist attacks. They don’t threaten the basic stability of the Philippines, but ″create an aura of instability,″ Lambertson said.

Several members of the committee urged the Reagan administration to take firmer steps in controlling Marcos, perhaps to the extent of putting him in an Immigration and Naturalization Service cell, taking away his telephone and restricting the movements of his wife and colleagues.