A third-year Harvard Law School student recently back from the South African territory of Namibia, said yesterday the South African anti-terrorist law "is so broad that practically any activity can lead to conviction," and that it is "a matter of administrative discretion to decide whom to charge and whom not to."

During a seven month stay in Namibia sponsored by a grant from the Lutheran World Federation, Ralston H. Deffenbaugh investigated the quality of legal defense for those prosecuted under the South African policy of apartheid.

Deffenbaugh plans to write his third-year Law School paper about a case involving six members of the South West Africa People's Organization (SWAPO), a group recognized by the United Nations as the representative of the Namibian people.

The six were arrested under South Africa's Terrorism Act for crimes ranging from allegedly giving $11.50 to an intermediary--who transferred the funds to persons who wanted to overthrow the South African government--to giving a Land Rover to another such intermediary.

Another was accused of providing transportation for persons who allegedly murdered a tribal leader.

Deffenbaugh said some of the witnesses at the trial testified later that the South African government had tortured them. The state's key witness, whom police detained for eight months without trial, was on one occasion denied sleep for a week, and received only two visits from his wife, Deffenbaugh said.

Under the Terrorism Act, the government can incarcerate anyone at the discretion of a minister of justice or of a police official over the rank of lieutenant-colonel, Deffenbaugh added.

He said none of the defendants had been accused of any personal acts of violence. He said the prosecution based its case entirely on circumstantial evidence, but that judges in political cases are "quite willing to believe anything the prosecutors say."

Two of the defendants received sentences ranging from five to seven years, while two other defendants--one allegedly involved in transporting the alleged murderers and the other allegedly involved in the Land Rover deal--were sentenced to death, according to Deffenbaugh.

The jury acquitted the other two defendants, but the case is being appealed.

Deffenbaugh added that this type of case is typical is South Africa, although the sentences were unusually harsh. He said their severity was probably due to growing government insecurity as a result of increasing guerrilla activities in the north and the fall of the once-friendly colonial regimes in neighboring Mozambique and Angola.

The United Nations and South Africa have each claimed that they have jurisdiction over Namibia. This dispute has not been resolved. In the interim, the South African government continues to rule the territory.