The mother, fiftyish and with a kerchief on her head in the fashion of Shiite Moslem women, said nothing. Her taxi driver said nothing, either.

Her friend, traveling with her in the uniform of the militia of cashiered Lebanese Army Maj. Saad Haddad--which is paid, armed and provisioned by Israel--summoned up his most eloquent arguments.

"I know her son, he is a good man, innocent," the militiaman said. But the Arab-speaking Israeli military policeman standing at the gate of the prison camp just kept repeating, "Mamnouh," meaning forbidden. "But I fight alongside your Army, and I tell you he's innocent," the militiaman insisted.

The Israeli policeman again said, "Mamnouh, mamnouh," and finally the militiaman, the driver and the mother got back into the taxi and drove back down the dusty, unpaved road.

They were neither the first nor doubtless the last Lebanese or Palestinians to come to the gates of this detention camp and inquire if their relatives were among the thousands detained by the Israelis since they invaded Lebanon June 6.

If anything, fewer families show up these days; word has spread since the camp was put into operation that the Israelis allow no personal visits.

Israeli detention of Palestinians and the conditions in which they have been held first in northern Israel and now in this camp still under construction in Lebanon have become subjects of controversy. For more than a month after Israel began taking prisoners in Lebanon, it declined to authorize customary prison visits by the International Committee of the Red Cross, causing the ICRC to set aside its traditional discretion and to drop public hints indicating its displeasure. The Israelis later yielded and the visits were allowed.

Now, new questions about the camp here at Ansar have been raised by an abrupt and unexplained suspension by the ICRC of those visits for three days, and by accounts of the conditions inside the camp coming from youths recently released from Ansar and from other accounts.

Israel has not granted open access to the camp yet for journalists covering the war from the Israeli side. A small pool of reporters was allowed to visit the camp last week to interview three prisoners chosen by Israeli authorities. The pool account of the guided tour distributed to foreign correspondents in Jerusalem contained no suggestions that the reporters had witnessed unusual or deplorable conditions there.

A request Monday from The Washington Post bureau in Jerusalem to visit the camp with an Israeli escort officer was turned down. Today, guards at the gate said entrance was prohibited without an escort officer and permission from the Israeli government.

The Israelis have established their prison camp in a region that has been hit hard by war during the past decade, as the Israelis and Palestinians have traded cross-border violence and Haddad's army has fought with the Palestinians and Lebanese leftist forces.

Many Lebanese in the south, while voicing sympathy for the Palestinians and their demands for a state, appear happy that the PLO and its weapons are for the most part gone from their cities, towns and countryside. And, while they say they hope that the time will come soon when all foreigners--including the Israelis--leave Lebanon, Lebanese officials do not often voice complaints about the presence of the Israeli soldiers.

The Israeli blitz has changed the face of the region. There appear to be virtually no Palestinian men between the ages of 16 to 60 free in southern Lebanon. Many of those who have not fled elsewhere have been detained in the Ansar camp, for which the Israeli government last week assigned a limit of 7,000 prisoners.

After the Geneva-based ICRC publicly hinted at its concern over Israeli delays in allowing detainees to be visited, Red Cross representatives were permitted into Ansar beginning July 18. By July 22, they had interviewed 2,059 detainees. But on that day, for the first time in its association with the Arab-Israeli conflict stretching back to the late 1940s, the ICRC took the initiative to interrupt the visits.

In keeping with the ICRC tradition of public discretion that has enabled it to work with both sides through a number of wars, no reasons were provided for the decision. The visits were resumed yesterday after what Frederick Steinemann, the Geneva-based ICRC press officer dealing with the Lebanese war, described as "technical difficulties" at the camp.

The resumption followed the arrival at the camp Sunday of Israeli Gen. Moshe Nativ, in charge of Army liaison with the ICRC, aboard a special C130 flight that landed at the neighboring airstrip the Palestine Liberation Organization originally built and the Israelis now have paved.

He was accompanied by Dominique Dufour, the head ICRC delegate in Israel.

Together they visited the camp, located six air miles inland from the Mediterranean, where bulldozers and earth graders still are leveling off the hilltop. It is surrounded by barbed wire, half tracks, watchtowers and earthen parapets.

Another 753 detainees were interviewed yesterday, and the ICRC delegates were seen leaving the camp this afternoon after another day's work.

Experts familiar with ICRC regulations speculated that serious overcrowding of prison facilities or possible refusal by the detaining authorities to permit private interviews at the prisoners' place of detention would result in a suspension of interviewing. But ICRC delegates firmly refused to shed any light on the decision.

So far the only detainees released since the invasion began--aside from about 600 Lebanese freed in Sidon in late June--were about 200 youths, aged 10 1/2 to 16, whom the Israelis liberated July 19 on humanitarian grounds.

According to the released youths, who had been nicknamed the "rocket-propelled grenade kids" for their proficiency with that shoulder-held antitank weapon on behalf of the PLO, the detainees at Ansar were kept in very crowded conditions.

The youths, in accounts that were confirmed independently, said detainees at the camp were housed in 500-man sectors each containing 12 tents, making for "sardine-like" overcrowding. The detainees were obliged to remain stretched out on an Israeli-provided blanket at all times during the day and night.

The camp contained no infirmary and only one doctor for the detainees, the youths said.

The exact number of detainees at the camp is not known. The present estimate suggests that it has reached the 7,000 limit that the Israeli government has assigned the camp.

Recent bus traffic suggests that Ansar, which is being expanded, may end up housing as many as 10,000 detainees--1,000 more than Israeli officials acknowledged they held earlier this month.

The youths said they had been driven up from the northern Israeli high-security detention center at Megiddo sitting on the floor of buses, their hands over their heads and being made to shout, "Bark like the dogs you are" and "Long live [Israeli Prime Minister Menachem] Begin, long live [Defense Minister Ariel] Sharon."

As difficult as conditions were at Ansar--before the Israeli authorities apparently took the corrective action that led to the resumption of interviews--the fate of the families waiting for the detainees' release is possibly even more worrying, according to international civil servants.

Perhaps as many as 10,000 Palestinians--most of them males--are unaccounted for in the Israeli-occupied territories in southern Lebanon, according to international civil servants and private and international relief and charity workers.

Some still are thought to be held in Israel--more than the officially acknowledged figure of 9,000 detainees. Others may be hiding in the countryside, while still others may have fled to the Bekaa Valley or West Beirut or have been killed or died of exposure.