Ayatollah Ruhollah Khomeini today granted a general amnesty for most political and common prisoners as the ruling Revolutionary Council appointed a committee to investigate growing complaints of vote-rigging in postrevolutionary Iran's first parliamentary elections.

Speaking on the eve of the Iranian new year holidays, Khomeini excluded from his amnesty prisoners accused of torture or killing or of ordering such crimes and those charged with misusing "the people's wealth and property."

Members of SAVAK, the now-dissolved secret police, the armed forces and other officials of the overthrown monarch were specifically included in the amnesty. Just how far-reaching the amnesty may be was not immediately clear, but Khomeini's message was clearly critical of the self-appointed vigilantes who have administered rough and ready justice since the February 1979 revolution, much to increasing public dismay.

The Revolutionary Council's decision on investigating the election was announced four days after the first round voting ended with the front-running clerical Islamic Republican Party under increasing attacks as the principal -- but far from only -- culprit in allegedly widespread irregularities.

The latest major figure to complain was Khomeini's older brother, Ayatollah Morteza Pasandideh.

In a letter to President Abol Hassan Bani-Sadr, he accused the Islamic Republican Party of "coercion, cheating and deception" in Khomeini's hometown of Khomein in central Iran. He charged that "even the judge and prosecutor have by intimidation, mass imprisonment and massacre led the election astray."

Bani-Sadr, who threatened to cancel the elections if the investigation proved widespread fraud, replied, "I cannot remain indifferent on this issue." He told Khomeini's elder brother, "Rest assured I shall act with full conviction."

In indirect reply, Hojatoleslam Ali Khamenehi, a Revolutionary Council member, played down the reports of irregularities as "not important" and said that "the Islamic Republican Party has not cheated at all."

In a similar show of self-assurance, Hojatoleslam Mohammed Javad Bahonar, another Islamic Republican on the Revolutionary Council said that "the probability of nullifying the elections does not exist."

Further embarrassment for the Islamic Republican Party came from their erstwhile allies, calling themselves "The Militant Clergy," who complained that the party railroaded them into accepting fewer slots than they felt they derserved on a "grand coalition" list.

Bani-Sadr's newspaper, Islamic Revolution, provided the best documented case of alleged vote-rigging. It involved the leftist Islamic Mujaheddine-Khalq party. They were accused of suborning a vote counter in Tehran, who added votes to their column while stealing them from the rival Islamic Republican candidates.

The painfully slow vote counting, which appears to have decelerated with every passing day, now shows Islamic Republican candidates accounting for a little less than two-thirds of the 70-odd outright victors who won the required absolute majority in the election's first round.

About 100 of 270 seats are to be decided in a runoff vote in early April, and the results of the remainder have yet to be announced.

Meanwhile, the Revolutionary Guards announced the arrest of Foreign Ministry employe Victoria Bassiri on charges of spying for American diplomat William Daugherty in return for $300 a month.

Daugherty, one of the estimated 50 U.S. hostages here, stands accused of working for the Central Intelligence Agency by the militant Islamic students who have occupied the American Embassy since Nov. 4.

The students apparently were behind the charges against Bassiri, who in the past year was said to have served as cultural and economic adviser at the Foreign Ministry before becoming deputy of its passport bureau.

Foreign Minister Sadegh Ghotbzadeh, who is at odds with the students, told reporters tonight he felt "definitely" under attack by them, but would "absolutely not resign."

"I don't give a damn about these attacks," he said.

The Islamic Republican Party newspaper, Islamic Republic, which is considered close to the students, demanded that Ghotbzadeh explain why Bassiri had not been purged earlier and blamed him for "weakness and indecisiveness."

As a crowning insult in its attack, the newspaper said Ghotbzadeh "considers the revolutionary occupation of the spy center," as the American Embassy is often called here, to be an act "in favor of Carter and U.S. imperialism."

Since the failure of the United Nations commission to resolve the U.S.-Iranian crisis last week, Ghotbzadeh has repeatedly attacked the students and accused them of undermining Iran's prestige and standing abroad, especially in the Third World.

At The Hague, meanwhile, the United States charged in the World Court today that the Iranian government was "an active participant" in the Nov. 4 assault on the U.S. Embassy in Tehran and that Ayatollah Khomeini incited the attack, the Associated Press reported.

"It is difficult to imagine a course of conduct more flagrantly in violation of uniformly recognized norms of international law," declared Roberts B. Owen, State Department legal adviser, as the court opened public hearings on the U.S. case against Iran.

[Iran is boycotting the proceedings and has ignored a Dec. 15 order by the court to release the hostages immediately.]