DETROIT (AP) — Singer and songwriter Sixto Rodriguez, who became the subject of the Oscar-winning documentary “Searching for Sugarman,” has died. He was 81.

Rodriguez’ death Tuesday in Detroit was announced on the Sugarman.org website and confirmed Wednesday by his granddaughter, Amanda Kennedy.

He died following a short illness, according to his wife, Konny Rodriguez, 72.

A 2013 Associated Press story referred to Rodriguez as “the greatest protest singer and songwriter that most people never heard of.”

His albums flopped in the United States in the 1970s, but — unknown to him — he later became a star in South Africa where his songs protesting the Vietnam War, racial inequality, abuse of women and social mores inspired white liberals horrified by the country’s brutal racial segregation system of apartheid.

Swedish filmmaker Malik Bendjelloul’s documentary “Searching for Sugar Man” presented Rodriguez to a much larger audience. The film tells of two South Africans’ mission to seek out the fate of their musical hero. It won the Academy Award for best documentary in 2013.

Rodriguez was “more popular than Elvis” in South Africa, Stephen “Sugar” Segerman said in 2013. The Cape Town record store owner’s nickname comes from the Rodriguez song “Sugarman.”

As his popularity in South Africa grew, Rodriguez lived in Detroit. But his fans in South Africa believed he also was famous in the United States. They heard stories that the musician had died dramatically: He’d shot himself in the head onstage in Moscow; He’d set himself aflame and burned to death before an audience someplace else; He’d died of a drug overdose, was in a mental institution, was incarcerated for murdering his girlfriend.

In 1996, Segerman and journalist Carl Bartholomew-Strydom set out to learn the truth. Their efforts led them to Detroit, where they found Rodriguez working on construction sites.

“It’s rock-and-roll history now. Who would-a thought?” Rodriguez told The Associated Press a decade ago.

Rodriguez said he just “went back to work” after his music career fizzled, raising a family that includes three daughters and launching several unsuccessful campaigns for public office. He made a living through manual labor in Detroit.

Still, he never stopped playing his music.

“I felt I was ready for the world, but the world wasn’t ready for me,” Rodriguez said. “I feel we all have a mission — we have obligations. Those turns on the journey, different twists — life is not linear.”

Konny Rodriguez said the couple met in 1972 while both were students at Wayne State University in Detroit and married in the early 1980s. Although still married at the time of his death, the couple had been separated for a number of years, she said Wednesday while shuffling through some of Sixto Rodriguez’s memorabilia.

“He loved college. He was born to be taught, to teach himself,” Konny Rodriguez said. “The music was more to bring people together. He would play anywhere, anytime. That’s where I noticed him. He was walking down Cass Avenue with a guitar and a black bag. He was a really eccentric guy.”

The two albums she said he recorded n 1969 and 1971 “didn’t do well.”

“I’m sure that was still in his head,” Konny Rodriguez added. “Then in 1979, I picked up the phone and it was a guy with an Australian accent who said ‘he must come to Australia because he’s very famous here.’”

She said they toured Australia in 1979 and 1981 and later learned about the impact of his music in South Africa.

“Apartheid was going on,” she said. “Frank Sinatra had a full-page ad, ‘Do not go to South Africa.’ We didn’t.”

After the end of apartheid, Sixto Rodriguez did travel to South Africa and perform in front of his fans there, she said.

“He did so well in South Africa. It was insane,” Konny Rodriguez said.

Sixto Rodriguez later pursued royalties he did not receive from his music being used and played in South Africa.

Some of Rodriguez songs were banned by the apartheid regime and many bootlegged copies were made on tapes and later CDs.