During one of his visits to the president, Mr. Pillay said, Mr. Zuma started off making small talk but was clearly exasperated, openly complaining about the questions lawmakers expected him to answer.
“He said, ‘Listen, I’m so tired and tomorrow morning I’ve got to go to Parliament,’” Mr. Pillay recalled Mr. Zuma saying. The president had faced volleys of outrage, especially over the lavish use of public money to upgrade his private homestead.
“‘Why must I go and answer questions in Parliament? Putin doesn’t go to Parliament to answer questions,’” Mr. Pillay recounted Mr. Zuma saying.
“That’s where he was” in terms of being open to scrutiny, Mr. Pillay said.
On top of that, one of Mr. Zuma’s sons was suspected of hiding profits from contraband cigarettes. Red flags had also emerged with a nephew’s used-car business and a foundation established by one of Mr. Zuma’s wives — all of which caught the attention of tax investigators, the four former officials said.
Mr. Pillay insisted that he never wanted to pursue Mr. Zuma directly through a formal investigation, but that the president seemed convinced otherwise.
“He got it into his head that we are monitoring him,” Mr. Pillay said.
Mr. Pillay was no stranger to conflict. He had been a commander in the military wing of the A.N.C. in exile, and later coordinated a clandestine operation to smuggle weapons and people into South Africa. Years later, at the tax agency, he led enforcement operations, hiring a coterie of former spies, police agents and investigators to go after tax cheats aggressively. His efforts earned him international recognition.
Under apartheid, people had avoided paying taxes altogether, many as a form of protest against the government. But democracy brought legitimacy and, with it, compliance, according to a World Bank study. Government records show that from the end of apartheid in 1994 through 2010, the number of people paying taxes nearly quadrupled.