Despite the campaign of Iranian revolutionaries against corruption under the shah, the Islamic republic is proving to be fertile ground for graft, bribes and rip-offs.

Far from being eradicated under the leadership of Ayatollah Ruhollah Khomeini, corruption in Iran still permeates many of the same official organizations that it did under Shah Mohammed Reza Pahlavi and is rife in some new ones, notably Khomeini's revolutionary committees, Kometehs , which field thousands of gunmen and run local affairs in many communities.

"It's a new bunch of thieves, with a little less finesse," a diplomat said.

"Corruption is worse in that it is no longer systematic," a banker said. "Nobody knows what the rules are anymore. You have a new set of opportunitiess around who are using their imagination to levy whether they think the traffic will bear."

Khomeini seems to be aware of the problem. He has warned his followers against showing the "ugly face of Islam," but so far his words have gone unheeded by many of those who constitute the new powers-that-be.

"What is important to me is not property, not the finances of the treacherous people," he pointedly told a group of revolutionary guards who came to visit him in the holy city of Qom recently.

"If the Komitehs do not act according to the precepts of Islam, and if the clergy who are at the head of society do not act with care, and if the government and army do not act with care . . . an ugly face of Islam will be reflected abroad."

Nevertheless, the problem of graft seems to be getting worse, according to Iranian and foreign sources here.

It is particularly serious in the customs administration and Iran's equivalent of the Internal Revenue Service, the sources say.

Recently, for example, the tax department of the Finance Ministry asked companies to come forward with their own tax assessments for the turbulent period last year when the government was paralyzed. If the returns were "reasonable," companies were told, they would not be questioned.

"A lot of companies did step forward," a banker said, "and right away the bargaining started" as officials demanded bribes for not arbitrarily assessing higher taxes.

In the customs administration, Iranians and foreigners report, officials routinely demand bribes to facilitate imports and allow people to ship their household goods out of the country.

One of the most extensive rackets, sources say, is the expropriation of property belonging to people who have been executed, jailed or fled the country. But increasingly, it seems ordinary citizens are seeing their property confiscated or in some cases, are being forced to pay protection money to armed men acting under the authority of the committees.

According to a senior official in one Tehran committee, members of the "Bonyade Mostazafin" or Poor People's Foundation, have profited from the auction of royal family belongings. He cited the sale last month of property the shah's older sister, Princess Shams, at her ornate palace near Karaj, west of Tehran.

Organizers of the auction, which was not widely publicized beforehand, participated in the bidding and went away with expensive cars, gold and silver tea services, silverware and jewelry "for a song," the committee member said.

The director of the foundation, which has taken over assets of the multi-billion-dollar Pahlavi Foundation, declined to be interviewed about the organization's activities.

But another foundation official confirmed that auctions were still taking place. He said expensive Persian carpets that belonged to "people condemned in Islamic tribunals" were auctioned privately once a week. He claimed the bidders were "professional carpet sellers."

Authorities have not yet disclosed what will become of other property expropriated from wealthy industrialists and businessman. "This is one of the deep dark secrets of the revolution," an economist said.

Meanwhile, militiamen in Khomeini's revolutionary committees have been cashing in with their own confiscations.

In one recent instance a groyp of Iranians was having a dinner party when a band of committee gunmen arrived and asked who owned a Chevrolet parked outside. One of the guests said it was his. The gunmen then charged it had been used to attack their committee headquarters, demanded the keys at gunpoint and drove the car away.

In another case, militiamen came to the home of a former senator and demanded a large sum of money not to arrest him. Shortly after the money was paid, however, another group came along and arrested him anyway.

Committee militiamen have also profitted from the exodus of foreigners who often have problems with landlords and customs officials when they try to move out.

"The Komiteh helps out a compromise, the Komiteh is part of that compromise," a foreign resident said. "They have to get their chop on everything that moves."

A major source of revenue of corrupt committee members, according to informed sources here, has been the sale of weapons and liquor.

"The Komitehs are the greatest fences for guns and booze," a diplomat said. He asserted that they even supplied weapons to some members of autonomy-seeking regional minorities who were involved in recent clashes with government forces.

Tehran's main committee recently tried to spruce up its Islamic image by ordering the destruction of more than $1 million worth of liquor at the Intercontinental Hotel. But this was only done after a near shootout with members of another committee who had concluded a deal with the hotel management to allow the sale of drinks to foreign guests.

A prime example of committee corruption has been the behavior of militiamen "guarding" the U.S. Embassy. The bearded leader of the original squad that moved in after the Feb. 14 guerrilla attack on the embassy has expropriated goods from the mission's commissary and taken a cut from the sale of embassy liquor stocks to other embassies in Tehran, according to informed sources.

Another racket at the embassy has involved the issuance of tourist visas to Iranians. Since the U.S. consular offices are closed, the embassy arranged to give out visas through local Iranian travel agents. Then officials discovered the agencies were charging up to $300 for an applicant to be put on the waiting list, and the serivce was dropped.

Although they are difficult to confirm, more stories are surfacing about demands by prison officials for bribes to obtain the release of jailed Iranians.

Even the U.S. Embassy was approached recently by Iranians who claimed to have contracts with the committee responsible for Tehran's Qasr Prison and said they could arrange the release of an Iranian employe of the embassy. The employe, Reza Amini, was jailed shortly after the revolution on unspecified charges.

Although corruption in the new regime is widespread, it is probably not as massive as the graft under the shah, and there have been numerous cases of "good deeds," residents say. For every instance of gunmen robbing houses in the name of a local mosque or committee, there have been others in which belongings have stored or protected.

But observers wonder whether these examples will be enough to keep the face of Iran's Islamic Revolutionary from growing yet uglier.