The division of Muhammad Ali's multi-million-dollar estate is expected to ignite World War III among his children, with the former champion boxer's wife set to inherit the lion's share of his fortune in his will.

The late boxing great, who died in June of last year aged 74, has left a larger slice of his estimated fortune of $100 million to his widow Lonnie than to his nine children, The Mirror reports.

His children, which include seven daughters and two sons, are expected to bank around $8 million each.

Ali's only brother, Rahman, is said to receive nothing in retaliation for his public feud with the boxer's widow.

A lawyer for the Muhammad Ali Trust, which controls his estate, said the boxer's will was drawn up in such a way to "to reflect his specific wishes and to protect his legacy".

"Once the money is there, expect the biggest war yet," the newspaper quoted an unnamed insider has saying.

"They all play nice-nicey now, but simmering tension goes back decades. None of the kids trust Lonnie, all are from different mothers and hate each other. World War Three is threatened and true feelings are expected to come flooding, and a few truths be told."

The simmering bitterness between the siblings was on display at Ali’s funeral, with actor Will Smith and boxers Lennox Lewis and Mike Tyson carrying the champ’s coffin rather than his sons.