Laila Ali has been boxing professionally since 1999
A planned high-profile charity boxing match in Nigeria involving the daughter of the former world champion, Muhammad Ali, has been postponed.
Laila Ali, a professional boxer in her own right, was to have slugged it out against Gwendolyn O'Neil from Guyana to raise money to combat Aids and people trafficking.
But promoters say she has not yet arrived in Nigeria.
Muhammad Ali went to Africa in 1974, knocking out George Foreman in a fight in Zaire (now the Democratic Republic of Congo) billed as the "Rumble in the Jungle" which became one of boxing's biggest upsets.
Organisers are hoping that Laila Ali's famous name will help them reach out to young men and women who they say are the main victims of Aids and human trafficking.
Ali - who started boxing professionally in 1999 and won her first world boxing title in 2002 - was to trade blows with O'Neil, a little-known Guyanese boxer, in Nigeria's capital, Abuja.
New York rap artists Ashanti and DMX were booked to perform in the same event, dubbed the "Battle of Hope".
More than six million people in Nigeria are believed to be living with HIV, the virus that causes Aids.
About 30,000 Nigerian women and children are estimated to be working as sex workers in Europe - victims of trafficking rings that smuggle women from Africa only to hold them in virtual slavery.