The cause was complications from pneumonia, said his son Michael Sparks.
Mr. Sparks was a fifth-generation white, English-speaking South African and grew up on a farm in a community where all of his playmates were black. Not until boarding school was he initiated into white society, an upbringing that allowed him to develop what he described as “an empathy with the black people that enabled me to go in and speak with them and find out what was happening.”
He was 15 when apartheid rule was established in 1948, codifying rigid racial segregation in South Africa and reserving political power as well as economic and educational privileges for the nation’s white minority. Shortly thereafter, fresh out of high school, Mr. Sparks entered journalism.
“I was seeing police folk beat up black folk,” he once told C-SPAN interviewer Brian Lamb. “And it horrified me.”
For much of the rest of his life, Mr. Sparks sought to use the power of the press to lay bare the injustices of apartheid. He wrote for years for publications including The Washington Post, the Economist and the London Observer. But he was perhaps best known as editor, from 1977 to 1981, of the Johannesburg-based Rand Daily Mail, the country’s most high-profile liberal newspaper.
Early in Mr. Sparks’s leadership, the Rand Daily Mail weathered a government reprimand after it helped discredit official reports that Steven Biko, a 30-year-old anti-apartheid activist, had died of a hunger strike while in police custody — when in fact his autopsy showed evidence of brain damage. A pathologist had contacted Mr. Sparks and, swearing him to confidentiality, revealed to him the contents of the postmortem report.
The newspaper later uncovered a scandal in which government officials were implicated in a plan to secretly divert millions of public dollars to fund a propaganda campaign aimed at currying favor in South Africa and abroad for the apartheid system.
The scandal led to the resignation of John Vorster as prime minister in 1978 and then as president the following year. In recognition of the reportage, a media organization named Mr. Sparks an “international editor of the year” in 1979.
Two years later, the Rand Daily Mail’s leadership removed Mr. Sparks as editor in what was widely understood as an effort to tamp down the publication’s political engagement.
“They had never liked the vigor with which it exposed the iniquities of apartheid,” Mr. Sparks wrote in The Post in 1990, “nor the heat this brought from the government, and when the paper began losing money, they contended it was because it was selling too many copies to blacks, who were of little value to advertisers, and too few to the wealthy whites.”
The ownership shuttered the newspaper in 1985. By that time, Benjamin C. Bradlee, The Post’s executive editor, had hired Mr. Sparks as a special correspondent, or stringer, in newspaper jargon. He remained a regular contributor to the newspaper through the collapse of apartheid in 1994 and beyond.
Mr. Sparks tussled frequently with state authorities. In 1983, he was charged with breaching internal security laws by quoting a “banned person” — Winnie Mandela, then the wife of imprisoned African National Congress leader Nelson Mandela — and by reporting that the South African security police operated an assassination unit.
Mr. Sparks’s wife, Suzanne, an anti-apartheid activist, was charged with obstruction of justice for allegedly helping arrange the removal of documents from her husband’s office. All the charges, which carried the potential of prison time, were eventually dropped.
Throughout his career, Mr. Sparks was undeterred by threats to his safety, whether during uprisings in black townships or facing government intimidation. Glenn Frankel, The Post’s southern Africa bureau chief from 1983 to 1986, recalled in an e-mail that “there were times when there were so many wiretaps on the office phone that all we heard was click after click for the first 15 seconds of every call. No matter. He kept working.”
Allister Haddon Sparks was born in Cathcart, in South Africa’s Eastern Cape province, on March 10, 1933.
He worked for newspapers in South Africa and England before joining the Rand Daily Mail in 1958, where he was a political correspondent before ascending the editorial ranks. After a closure that lasted years, the newspaper was revived in 2014.
Mr. Sparks, who appeared frequently on U.S. television and radio, distinguished himself in the later years of his career as an author. His books included “The Mind of South Africa” (1990), which was modeled on American journalist W.J. Cash’s 1941 volume, “The Mind of the South,” and in which he explored the centuries of history that helped create the country’s entrenched psychology.
Writing in the New York Times, journalist and author Adam Hochschild described Mr. Sparks’s book “Tomorrow Is Another Country” (1995) as “a gripping, fast-paced, authoritative account of the long and mostly secret negotiations that brought South Africa’s bitter conflict to its near-miraculous end” and “the work of a fine reporter who was in the right place at the right time.”
Mr. Sparks’s other books included “Beyond the Miracle: Inside the New South Africa” (2003), “First Drafts: South African History in the Making” (2009) and “Tutu: Authorized” (2011), a biography of the Anglican Archbishop Desmond Tutu written with Tutu’s daughter Mpho A. Tutu. Mr. Sparks’s memoir, “The Sword and the Pen,” was released this year.
His first wife, Mary Rowe, whom he married in 1957, died in 1972. Sue Matthey, whom he married in 1973, died in 1999. His third marriage, to Jenny Gandar, ended in divorce.
Survivors include three sons from his first marriage, Simon Sparks of Rivonia, South Africa, Michael Sparks of London and Andrew Sparks of Kenilworth, England; a son from his second marriage, Julian Sparks of Santiago, Chile; and six grandchildren.
Mr. Sparks wrote most recently for The Post in 2004, on the 10th anniversary of Mandela’s swearing-in as his country’s first black president.
“It was the most stirring moment of my life,” Mr. Sparks wrote. “For more than 40 years as a journalist in South Africa, I had written about the pain and injustices that apartheid inflicted on people. I had been harassed and threatened by a white regime that regarded me as a traitor for doing this, and here at last was a kind of vindication or triumph.
“It is a terrible thing to feel alienated from one’s own people,” he continued. “. . . I could not identify with the land of my birth because it stood for things I abhorred; I felt no sense of patriotism when I heard my national anthem or saw my national flag. But on that day in 1994, as I stood before a new flag, listening to a new anthem, watching a new president being sworn in, I felt, yes, my very first twinge of national pride.”