More than three months after the massacre that shocked the world, the men who planned and led the slaughter of still untotaled hundreds of men, women and children at the Shatila and Sabra refugee camps here are going about their business, as powerful as ever.

The government of President Amin Gemayel appears to be doing little to track down and punish them. Western diplomats report signs that Gemayel has made a tacit pact with these same men that allows them to continue above the law in pursuit of their vision of how to make Lebanon safe for the religion they profess.

Phalangist commanders identified by a variety of diplomatic, intelligence and Christian sources as being responsible for the massacre that took place between the evening of Sept. 16 and the morning of Sept. 18 are reported today at their posts in the Lebanese Forces militia created and commanded by Gemayel's assassinated brother Bashir.

It was Bashir Gemayel's death in a bomb explosion in his party headquarters Sept. 14, nine days before he was to assume the presidency now held by his brother, that set off the chain of events that led to the Israeli military occupation of Moslem West Beirut and the subsequent entry of their Lebanese Forces allies into Shatila and Sabra.

In Israel, the fact that its government approved the Christian militia's entry into the camps and that its military then provided logistical support for their operations was enough to shake the government of Prime Minister Menachem Begin and force an independent state inquiry into possible government derelictions of duty.

In Lebanon, the official reaction was to deny that the Christian militia was actually involved and to appoint the powerless Lebanese Army's Christian prosecutor general to conduct what even government supporters admit was a perfunctory, empty investigation.

While the Israeli investigating commission has gone as far as calling Begin, Defense Minister Ariel Sharon and senior military and intelligence officials to testify about the exact knowledge they had at the time the massacre was going on, the Lebanese investigator has not even gone to the Lebanese Forces' East Beirut headquarters to ask their commanders where they were at the time of the crime.

There are signs, according to one distressed western diplomat closely following the post-Shatila events, that even this pretense of an investigation is about to be closed. "We have reports the so-called investigation is going to be allowed to expire on the grounds that since the Lebanese government had no authority over the camps at the time, it has no official competence to probe the affair," the diplomat said. The premise, he indicated, appeared to be that since there were no trustworthy Lebanese officials on the ground to provide the sort of official testimony the government requires, there was no point in continuing the investigation.

It is a measure of the impotence, indifference or policy of the Lebanese government that to this day no systematic effort has even been made to determine the exact extent of the carnage

Statistics being hard to come by in the Third World, there are varying numbers given for the Shatila dead, depending on the source consulted. But no one in the government has even bothered to probe into what are believed to be mass graves dug by the two bulldozers that were provided to the militia by the Israeli Army. Women in the camp have told numerous witnesses of seeing bodies dumped into bulldozed holes by the scoopful. Nor have officials made any effort to establish what happened to hundreds of people whom the camp residents still list as missing.

Sharon last week came up with a figure of 479 dead, which probably is as accurate a count as exists of the bodies found above ground, in homes where doors had been kicked down, in patios where victims had been surprised, or in the streets and alleys where many appeared to have been gunned down trying to flee. At one session of the Israeli investigating commission Sharon cited a figure as high as 700 to 800, but in Lebanon no one has done enough investigating to confirm or deny such numbers.

In East Beirut, one Christian militia unit commander who boasted to an old friend that he had been in the camp for the massacre was asked whether he knew how many were actually killed. "Nobody is ever going to know that unless one day Beirut decides to build itself a subway system," was the chilling reply.

Among the Christians of East Beirut and the Moslems of the western sector, the official denials of the Christian militia's involvement by President Gemayel, by his father's Phalange Party, by the spokesmen of the Lebanese Forces are still cited when the question is brought up. But there is an undercurrent of tension that suggests that it is dangerous to discuss the question. Moslem politicians, at heart seething about the dreadful deed, maintain their silence in public, privately attributing this to the higher priority of preserving the mythical national unity between Lebanon's Christians and Moslems.

The Lebanese Forces remains an independent entity answerable only to its own leaders. Since the Israeli invasion of southern Lebanon and the subsequent evacuation of the Palestine Liberation Organization fighters who once ruled there, the Lebanese Forces have become even more powerful.

Exactly what President Gemayel's relationship is with the powerful private militia that followed his dead brother is not totally clear. What is known is that the president has not tried to disarm the militia that rivals the national army he is seeking to build, and of late there is talk of an understanding between Gemayel and Fadi Frem, the commander-in-chief of the Lebanese Forces hand-picked by Bashir Gemayel two days before his death.

"It is not clear who has coopted who," said one western diplomat here, "but from what is being said and what is being done it is evident that Amin [Gemayel] and Fadi [Frem] are seeing eye to eye on most things these days."

Frem and the other key members of his command whom both western diplomatic and Christian political sources have pinpointed as the men of Shatila are very much still in business, operating as if nothing had happened.

Frem, who presided over the war council that sent his forces into the camps, today sits in the office of his martyred mentor in the militia headquarters near the port in East Beirut, directing his men's new campaign against the Druze in the Chouf Mountains outside Beirut. That campaign, like the militia's opening of offices in Moslem West Beirut, has alarmed those who wanted to believe that once the PLO left harmony and peace would reign.

Frem's security chief, 28-year-old Elie Hobeika, a man who learned his craft at the Christian siege of the Palestinian refugee camp of Tel Zataar during the 1975-76 civil war, where the final slaughter of civilians was to dwarf what happened in Shatila, is also back at his headquarters office, according to western diplomats, after a brief diplomatic holiday in Europe following the massacre. Hobeika, who many believe is the power behind Frem's throne, has been pinpointed by a variety of reliable sources as the overall commander of the Shatila operation.

Dib Anastas, who led his elite military police units, with their distinctive red striped helmets, in the camp, is still in charge of the force, despite the spreading of rumors in Beirut that he had been somehow implicated in Bashir Gemayel's death.

Joseph Edde, the head of the militia's so-called Occupied Territories Office that oversees the troops in southern Lebanon and a leader of the black-bereted commando units in the camp, was last seen as part of a Lebanese Forces delegation negotiating a cease-fire with the Druze in the Chouf.

Marun Mishalani, another alleged participant in the Shatila rampage, has also been reported fighting around the Chouf town of Alayh, scene of countless firefights, murders and kidnapings in recent weeks.

Walking once more through the desolation of Shatila in a fading winter's light, the only fleeting consolation for unarmed Palestinian civilians is the sudden sight of a red, white and green Italian flag flying above a sandbagged gun position. Six smiling Italian soldiers look down over the camp, shouting "Ciao!" to passersby, especially if they are young women.

Members of the 4,300-man multinational force that includes French paratroopers and U.S. Marines sent to Beirut in the wake of the massacre, the Italians also patrol the meandering alleyways of the camp at night.