A proposed international commission to investigate alleged crimes of deposed Iranian Shah Mohammad Reza Pahlavi is expected in Tehran "in three or at most four days," an Iranian Foreign Ministry spokesman said there today.

But spokesman Nasir o-Sadat Salami told the Reuter news agency in Iran that "it is certain that the hostages will not be released during the coming week."

In an interview here with The Washingtn Post, Foreign Minister Sadegh Ghotbzadeh said that release of the American hostages is not a matter of just 10 days or two weeks and that "false hopes" should not be raised.

The hostages "obviously" will not be released until after Washington drops all economic sanctions against Iran, including the freeze on Iranian bank holding, Ghotbzadeh said. But he insisted these are not "conditions' for the hostages' release.

Ghotbzadeh's statements appeared to indicate Iran's unwillingness to be locked into a time frame for release of the hostages, but they also were an indication of flexibility on conditions that would lead to their release.

The foreign minister, here as part of a tour to mend Iran's relations with Western Europe, also acknowledged that he does not expect to continue in his current position once newly elected Iranian President Abol Hassan Bani-Sadr forms his Cabinet. But Ghotbzadeh insisted that he and Bani-Sadr have been in close contact and that there is no disagreement between their positions.

Ghotbzadeh said, somewhat unexpectedly, that the U.N. investigating commission Secretary General Kurt Waldheim is about to name would not investigate the role of the United States in Iran, but would be confined to the alleged crimes of the deposed shah and his family's alleged "embezzlement" of Iran's resources.

[An announcement of the formation of the U.N. commission in New York was again delayed, reportedly by Iran's failure to set a definite time for freeing the estimated 50 American captives in Tehran. Details, Page A37.]

The foreign minister said that there is no question of transferring the hostages to a third party for safekeeping, which has been suggested by sources at the United Nations.

"They're all right," he said. "Why do that?"

Militants holding the hostages in Tehran today issued a statement underlining the strength of their position.

"By having the American spies in our hands, we are in a position of initiative and power," the statement said. "In spite of the fact that the United States has vast military and economic facilities, it can't help obeying the will and demands of our imam [revolutionary leader Ayatollah Ruhollah Khomeini], and the Iranian people about the extradition of the shah and his wealth."

But the return of the shah and his fortune to Iran apparently is not at issue now in negotiations for the release of the hostages.

Bani-Sadr last night told Iran's Pars news agency that once the United States meets Iran's conditions, which include some sort of U.S. admission of guilt in Iran and promises it will not interfere in Iran's internal affairs or efforts to obtain the shah's extradition from Panama, "then preparations will be made about the hostages."

"There has never been a secret plan about the release of the hostages." Bani-Sadr said. "If the first steps are taken, maybe this conclusion will be reached."

In a televised speech reported by Reuter from Tehran today, Bani-Sadr said he could not order militants holding the American hostages to release them simply because the United States wants them to.

"They certainly will not do it," Bani-Sadr said.

In explaining the demands he said Iran has made of the United States in return for releasing the hostages, Bani-Sadr said he has "been told that one of the conditions, which concerns the United States condemning its past record" in Iran "is humiliating for the United States.

"We say that we are pleased to confess our past mistakes," Bani-Sadr said. "How can I tell the students to release the hostages, just because the United States wants it?

"If we want to have a new relationship with the United States in the future, my people must be confident we have severed previous relations and that those relations won't be restored."

In another interview with Pars, reported by Agence France-Presse from Tehran, Bani-Sadr said the Islamic students holding the hostages at the U.S. Embassy must not interfere in affairs of state.

"They are brothers and we love them well," Bani-Sadr said, according to the news agency. "But that is not in any way affected with affairs of state. They must not intervene."

Bani-Sadr visited yesterday with Khomeini, who has been hospitalized since early last month, and reportedly has Khomeini's approval for a plan for release of the hostages. Although the president said yesterday he would also meet with the militants, there was no indication that he did so today.

In Paris, Ghotbzadeh said the proposed commission would be "more in the nature of a grand jury" than the approach advocated by French communist lawyer Nuri Albala of a "Third World Nuremberg tribunal" molded after the international war crimes trials of the leaders of Nazi Germany.

Attempts to organize the investigation along those lines were "a dirty trick" that the communists tried to play on Iran in an attempt to take over the Iranian case in the service of international communist propaganda, Ghotbzadeh said.

The new guidelines apparently worked out for the investigation could have the effect of making an Iranian-American reconciliation easier.

Former Irish foreign minister Sean MacBride, who was prominently mentioned for the presidency of the commission but apparently has been dropped from consideration for its membership, let himself be maneuvered by those who favored the communist approach, Ghotbzadeh said.

Reached in Dublin, MacBride expressed surprise at reports he would not be named to the commission. He said his political views were "well-balanced." But Ghotbzadeh made it clear that Iran, as well as the United States, was concerned about MacBride's closeness to the Soviets.

Our problem is with the United States, not to make propaganda for the communists," he said. "We made our revolution all alone, and we intend to keep our independence."

Earlier Ghotbzadeh told a press conference that the U.N. commission should hold its sessions in Tehran, since that is where the acts under investigation took place. He said the Iranian Justice Ministry would make presentations to the commission and witnesses who would testify about the tortures they suffered under the shah.

The deposed imperial family, the Pahlavis, reacted sharply to the news that they would be the ones under investigation rather than the United States. Marc Valle, a lawyer here for Princess Ashraf, the shah's twin sister, and her daughter, Princess Azzadeh, a leader in the monarchist movement, called The Washington Post to say, "The Pahlvis are going to fight back. They won't be the scapegoats." He said he would go to Tehran to represent them.

Among other things, he said, they would show that there are many other guilty persons, including Waldheim.

"He was a courtesan, he kissed the shah's hands, he clinked glasses with Princess Ashraf," Valle said.

Asked in a news conference if U.S. journalists would be allowed to return to Iran to follow the work of the U.N. commission, Ghotbzadeh said "I'll try my best. I hope the American media tries to be more responsible as well."

It is understood that a decision could come next week. It seems likely that permission for U.S. reporters will be granted case by case rather than a blanket reopening of the doors to the American press.

Meanwhile, Louis Pettitti, 64, former president of the Paris bar association who it is believed will be a member of the commission, said he thinks it is quite possible for the panel to issue a preliminary report of its findings within 15 days after starting its work.

Ghotbzadeh said yesterday that the commission should spend just 10 to 15 days before reaching its conclusions. Pettitti's comments seemed to indicate willingness to offer a compromise on that point.

The French lawyer said that the commission would "surely" meet with the U.S. hostages if it goes to Tehran.

Pettitti said in a telephone interview that as soon as Waldheim announces the membership, the commission can hold an organizing meeting in New York or Geneva within 48 hours and then leave rapidly for Tehran after having brought together a staff.

The French lawyer said that Iran might be willing to consider more favorably a request for the freeing of the hostages from the commission once it has issued a preliminary report. He suggested that the hostages could then be released to a neutral third party like the International Red Cross.

Ghotbzadeh said he has not suggested that the hostages would be freed even after the U.N. commission has finished.

"Why is all this false hope being created," he asked. "I have been talking about ending this crisis step by step. There is no point in saying this or that will happen next. Then, if one of the things you say doesn't happen, there is disappointment. I can't guess how much time it will be before the hostages are let go and Bani-Sadr doesn't know either."

He said that Iran would not ask the United States to end the economic sanctions.

"If they have done it, they will have to end it," he said. "Obviously, they'll have to end it before we release the hostages. You'll have to give our money back sooner or later -- with interest."

As for himself, he confirmed that he does not expect to remain as foreign minister once a Cabinet is formed after the forthcoming parliamentary elections.

He said that might take as much as three months. A candidate against Bani-sadr in the presidential elections, Ghotbzadeh got less than 1 percent of the vote. He is not running for parliament.

His "primary responsibility," he said, is not his job as foreign minister but his position as a member of the Revolutionary Council, which has been serving as the ailing Khomeini's main instrument for ruling the country.

Meanwhile, Iranian media reported that the unofficial death toll in severe flooding in the oil-rich southwestern province of Khuzestan rose above 250.

Pars said two people died and two were missing after a helicopter carrying aid to the disaster area crashed near the provincial capital of Ahva today.

Tehran Radio said the flood level continued to recede.

Khomeini made an evening television appearance from his hospital room to offer condolences to the families of those killed in the flooding.