Nigerian-born author Chimamanda Ngozi Adichie's novel has been voted the best book to have won the Women's Prize for Fiction in its 25-year history.

Adichie, who won the prize in 2007 for her 'Half of a Yellow Sun', was selected in a public vote from a list of 25 winners.

The one-time award marks the anniversary of the prize, previously called the Orange Prize and the Bailey's Prize.

Half of a Yellow Sun is set in Africa's most populous nation, Nigeria during the Biafran War.

The novel explored the end of colonialism, ethnic allegiances, class, race and female empowerment.

"I'm especially moved to be voted Winner of Winners because this is the prize that first brought a wide readership to my work, and has also introduced me to the work of many talented writers", Adichie said.

The book garnered global acclaim when it was published in 2006.