Affair Clouds Career of Anti-Apartheid Leader Boesak : South Africa: He resigns his pulpit over a tryst with a married woman. But activists do not expect it to hurt the black liberation struggle.

With only the clerical cloth and his international stature as protection, the Rev. Allan Boesak has endured a decade of arrests, detentions, charges, death threats and tear gas in a defiant fight against apartheid.

But today, one of South Africa’s most widely known anti-apartheid figures has become deeply embroiled in personal problems of his own making, and his political and professional ascension have been seriously undermined.

The bespectacled pastor--the dynamic leader of South Africa’s mixed-race population and patron of the giant United Democratic Front anti-apartheid coalition--took to the pulpit of his Cape Town church this week to tearfully announce his resignation as minister.

The reason: revelations that he was having an affair.

“This is one of the darkest days of my life,” he told parishioners Sunday, some of whom began to weep. He apologized “for all the pain I have caused” and said he spoke “with deep regret of the high price” he would have to pay.

Boesak, a 44-year-old father of four, denied that anything “immoral” had taken place between him and Elna Botha, a 30-year-old executive with the state-run television network. Botha, who is married to a TV news reader, is the niece of a former government Cabinet minister who once took away Boesak’s passport.

A day before Boesak’s announcement, he and Botha were confronted at a Cape Town hotel by a reporter for a government-supporting newspaper, Die Burger, which said it had been tipped off by a maid at the hotel. The maid also had called Boesak’s wife, Dorothy. Boesak told his congregation that his marriage had been breaking up before he met Botha.

Boesak has made no public comments since that emotional church meeting. Church officials say they are awaiting Boesak’s formal letter of resignation before deciding whether to accept it.

Still in limbo are Boesak’s prestigious positions as president of the World Alliance of Reformed Churches, to which he won unprecedented reelection last year, and as moderator of the 800,000-member Dutch Reformed Mission Church, the racially segregated Calvinist denomination for people of mixed race, who are officially classified in South Africa as Colored.

Boesak’s political credibility is bound to suffer, anti-apartheid activists say, but they foresee no permanent damage to the black liberation struggle, which has been largely taken over by returning political exiles and freed prisoners such as Nelson Mandela.

Boesak’s role in the struggle, like that of his friend, Anglican Archbishop Desmond M. Tutu, was created in the early 1980s by the disappearance of anti-apartheid leaders, thousands of whom were arrested or fled the country.

Tutu and Boesak, shielded from the most serious government action by their growing international reputations and their clerical collars, filled in the gap by defying the authorities and speaking for those who could not.

But those days have gone. The then-banned African National Congress now is a legal political organization inside South Africa. Mandela and dozens of other ANC and United Democratic Front leaders are free, political exiles are beginning to return and the government has lifted most of the curbs on political expression that Boesak and Tutu fought.

“Boesak was a churchman with a public conscience but . . . always more politically important outside of South Africa than inside,” said Mark Phillips, a researcher at the Center for Policy Studies in Johannesburg.

In fact, Boesak has been showered with international honors, including the Martin Luther King Jr. International Award, bestowed by the Los Angeles chapter of the Southern Christian Leadership Conference in 1987. Two years earlier, he received the Robert F. Kennedy Memorial Human Rights award, but his wife and 8-year-old son had to accept it for him because the South African home affairs minister, Stoffel Botha, had confiscated his passport.

“Since political organizations have been legalized, the ‘political priests’ have been largely returned to their priestly role,” Phillips added, “and his political significance had waned before this scandal.”

Other political and church leaders say it is too early to count Boesak out.

“It’s a matter of great sadness,” said Tutu, the 1984 Nobel Peace laureate. But “people should not think this is the worst kind of sin, and we hope that Allan will work through this crisis and be rehabilitated so that his tremendous gifts are not lost to the church and the country.”

Murphy Morobe, publicity secretary for the United Democratic Front, said he doubted that “this would be the death knell” for Boesak, who seven years ago helped found the coalition of more than 700 anti-apartheid groups.

Boesak’s illustrious political and church career has been marred once before by a similar scandal. In 1985, security police tape-recorded reported romantic liaisons between the cleric and a female church worker, who was white. Boesak admitted only that “a unique relationship” existed between them.

Boesak came to world attention in 1982 when he led a successful campaign to have apartheid declared a heresy by the World Alliance of Reformed Churches. The alliance then suspended two white branches of the South African church for supporting apartheid and elected Boesak president.