A six-man investigative team of the South African Catholic Bishops' Conference issued a report here today detailing allegations of wide-spread atrociteis against civilians by South African soldiers pursuing guerrillas in Namibia.

The investilgators, who visited the war zone in northern Namibia in September, said civilians told them members of the South African Defense Force had pillaged villages and tortured people while hunting insurgents from the South-West Africa People's Organization (SWAPO).

They also heard claims that people were shot and beaten to death and that some soldiers stood guard over families while other soldiers took the women into the nearby bush and raped them.

The investigators said they found widespread support for the guerrillas among Namibian civilians. The bishops called for a swift political settlement and independence for the disputed territory and for withdrawal of South African forces.

An official Defense Force spokesman, Brig. Kobus Bosman, called the allegations "a mere repetition of the one-sided propaganda regularly churned out by the SWAPO terrorist organization and its communist allies."

Bosman said the charges were "vague and unsubstantiated," and questioned why the Catholic bishops had not presented their evidence to a military board of inquiry appointed to investigate such matters.

At a press conference today, Archbishop Denis Hurley, president of the biracial conference and one of the six senior Catholic leaders who conducted the inquiry, said the investigators had not found direct evidence of atrocities and had only the allegations of the people theey interviewed.

But Hurley said the detailed accounts they had heard "had the ring of truth about them." He said the investigators had questioned 180 people, 17 in detail, in visits to Windhoek, the Namibian captial, and to the northern war zone, where they spent four days. The area is inhabited by the Ovambo tribe, which provides SWAPO with most of its domestic support.

The conference, which says it represents more than 2 million Roman Catholics in South Africa and neighboring territories, has long criticized the government's apartheid policies and alleged human rights violations. But the report details the most serious charges yet against the military.

The investigatiors said Namibian civilians fear the South African forces as an occupying army. They said South African troops are known in the local Ovambo language as omkakuknya, which means "bloodsuckers" or "bone-pickers."

The report contrasts sharply with the view expressed by U.S. Secretary Alexander M. Haig Jr. on Aug. 28, when he accused SWAPO of "inflicting bloodshed and terrorism upon the innocent noncombatant inhabitants of Namibia."

It has been a top priority of the Reagan administration's Africa policy to secure free independence elections in the sparsely populated territory twice the size of California. The area has been administered by South Africa since World War I.

South Africa has an estimated 50,000 troops along the 1,000-mile frontier with Angola as a defense cordon against SWAPO guerrillas based across the border.

South Africa says its troops are protecting the local population from the insurgents, whom it portrays as ruthless terrorists trying to eliminate their democratic opponents and take over Namibia on behalf of the Soviet Union.

Hurley said the investigation stemmed from complaints of atrocities that an official of the conference heard while on a tour of Namibia early last year.

In addition to Hurley, the others who conducted the inquiry were Archbishop George Daniel of Pretoria; Archbishop Peter Butelezi of Bloemfontein; bishop Mansuet Biyase of Eshowe, in Natal Province; Bishop Manfred Gattshalk of Oudts-Hoorn, Cape Province, and Msgr. Marius Banks, of Volksrust, Orange Free State.

The report said the group found pervasive fear of the South African security forces among the local civilian population. Emergency laws empower the security forces to detain and interrogate people without charges, and the report said the detentions areoften accompanied by beatings, torture, spare diet and solitary confinement.

"Reports indicate that in searching out SWAPO guerrillas, the security forces stop at nothing to force information out of people," the report said. "They break into homes, beat up residents, shoot people, steal and kill cattle and often pillage stores and tea rooms."

It added: "When the tracks of SWAPO guerrillas are discovered by the security forces, the local people are in danger. Harsh measures are intensified. Peiople are blindfolded, taken from their homes and left beaten up and even dead by the roadside. Women are often raped.

"There is no redress because reporting irregularities or atrocities to commanders is considered a dangerous or fruitless exercise."

The report said the investigators were also told that the security forces drove around with the bodies of killed SWAPO guerrillas danling from their vehicles as a warning to civilians not to join the movement.

"We were told that school inspectors will not travel by official transport nor accept an Army escort," the report said. "The image of anything official or connected with the Army is either too hateful or too dangerous."

Referring to charges that SWAPO is a communist organization, the investigators say that while the group receives arms supplies from communist countries and has imbibed some ideological rhetoric, most of the people they spoke to regard it as primarily a liberation movement.

"Whatever the Marxist tendencies of SWAPO, it seems to be a movement with powerful popular support, inspiring little apprehension in the majority of Christians in Namibia and looked upon as certain to win any free and fair elections held under United Nations supervision," the report concluded.