The release of four black activist leaders after only five days' detention under South Africa's emergency regulations normally would have been cause for rejoicing in Zoza township, outside the city of Grahamstown, which has been a major center of this country's prolonged racial crisis.

Instead, it has sown suspicion among the activist organizations and disrupted their protest campaign against the emergency regulations more effectively than did the initial arrests under those regulations, which went into effect two weeks ago.

The men are being accused of making a deal with their police interrogators. The allegation is that they were released on the condition that they call off a boycott of white shops in the city.

They deny making such a deal. The police say they "know nothing about it." But some local blacks remain unconvinced and are accusing the four men of being "sellouts."

"The security police knew exactly who the vulnerable people were, and they have exploited divisions in the community most successfully. There is total confusion now," said Priscilla Hall, a member of a white civil rights organization called the Black Sash, who has been monitoring the unrest in Grahamstown.

The incident points to the shrewd exploitation of detailed inside information by local police and illustrates the sophistication of the security apparatus that black activists confront here.

Douglas Rwentela, Zalisile Mkhontwana, Ntokalo Sandi and Madoda Mabhoza are all members of the executive committee of the Grahamstown Civic Organization, which has coordinated seven months of protest campaigning in the picturesque little city in the heart of eastern Cape Province, where the most violence has occurred.

All were arrested at their homes on July 21, within hours of the emergency declaration. As Rwentela later recounted in a telephone interview, the four were put in separate cells at the local police station. During the next three days, the men were interrogated separately by security police. They were freed after five days.

At the same time, Graco, as the civic organization commonly is called, was granted permission by the local magistrate, a state employe, to hold a meeting in Zoza's community hall. For five months, Graco had been refused permission under the security laws to hold a meeting or use the hall, and it became a matter for comment in the township that the prohibition was lifted right after the declaration of an emergency.

At the meeting July 28, Rwentela and Sandi urged that a month-long boycott of Grahamstown stores, intended to sensitize the white community to black grievances, be called off. Mkhontwana and Mabhoza did not speak but, according to people who were there, the two men indicated their support for the other two.

"There was great consternation and confusion," said one source, who asked not to be identified. "Many people in the audience accused the four men of being sellouts."

According to this source, one angry youth told the four men: "Nelson Mandela [imprisoned leader of the underground African National Congress] has been in jail for 21 years, and you have cracked after only five days."

Many people left the hall after what appeared to some to be an attempt by the Graco committee members to prevent black students from voting. Eventually only 192 out of an original audience of 1,000 voted, and a motion to end the boycott was passed.

Two representatives of a black labor union involved in organizing the boycott, the South African Allied Workers Union, spoke at the meeting against ending the boycott, and after the vote they dissociated the union from the decision to do so. The next day, both union members were detained under the emergency laws.

Rwentela denied in the interview that he or the other three had made a deal with their interrogators. The boycott was proving less successful and less well-organized than other Graco campaigns, he said, and committee members had decided before they were detained that, rather than continue something that was not working, it should be ended. They needed to get approval at a community meeting but had been unable to hold one before July 28.

Rwentela admitted that his interrogators had asked him about the boycott, and that he had told them of his belief that it should be ended.

Rwentela admitted, too, that his interrogators had been "hostile and aggressive" when they began questioning him, but that later their attitude had softened and they had become "more reasonable."

They told him that they regarded him as a moderate, Rwentela said, and when he was released, they said they "would be watching me and expected me to behave as a moderate."

"It could be that they had it in their minds that if they released us, we would end the boycott, but they did not say that to us or make it a condition of our release," Rwentela added. "They just let us go. There was no deal."

Graco's chairman, Billy Ndwebisa, who was not detained, said he accepts this explanation. He confirmed that there was a feeling in the committee before the detentions that the boycott should be ended, and said it was he who persuaded the local magistrate to grant permission for the July 28 meeting.

The suspicions persist, however, and some of the four ex-detainees now have posted guards at their homes. They fear that they may be targeted for attack as "sellouts" to the white-minority government.

The incident has split Graco and caused dissension between it and other activist groups that have worked together organizing the black protest campaign.

"People in the township are confused and angry," said Black Sash's Hall. "They don't know whom to believe, and they don't seem to know what is going to happen next. The whole campaign has come to a standstill.

"The security police seem to have had detailed inside information about the organizations," Hall added. "They knew who to arrest and how to sow suspicion. They have been very intelligent."