Luandino Vieira, the 2006 Camoes literature prize winner, has turned down the 100,000-euro prize citing personal reasons, Portugese media reported on Thursday.
Vieira, 71, was the first winner to turn down the top Portuguese language literature prize since the award was launched in 1989 by the Portuguese and Brazilian governments.
The two governments each give 50,000 euros to make the prize total.
According to one of Vieira's friends, the Portuguese-born Angolan writer has been leading a reclusive life, which may partly explain why he turned down the award.
Portuguese Culture Minister Isabel Lima said the Portuguese government respected Vieira's decision and would reserve the money for him.
The six-member jury of the prize said Vieira's writing represented "a most original voice in Portuguese-language literature." They added that it recreated the language and influenced "generations of writers" in Angola and elsewhere.
Vieira, the third African author who was awarded the prize, was arrested several times by Portugal's political police for his opposition to Portugal's colonial rule of the southwest African country which ended in 1975.
He spent eight years in prison in the notorious Tarrafal political jail in Cape Verde. He now lives in northern Portugal.
The Camoes prize is named after Luis de Camoes, the great Portuguese poet of the 16th century.