Five of James Brown's children are challenging their late father's will, according to court documents.
Brown died of pneumonia a year ago
Most of Brown's estate was left to trusts set up to educate disadvantaged young people and his grandchildren.
But some of his children claim three of Brown's former advisors convinced the singer to create the trusts so they could profit from managing them.
One advisor, Buddy Dallas, described the attempts to challenge the will as "an act of desperation".
He denied the allegations.
"No-one told James Brown what to do," said Mr Dallas, adding that if he had wanted to use his influence for financial gain, "I would have just influenced him to give me something."
'Clouded in mystery'
The Brown children challenging the will in Aiken County Probate Court, South Carolina, are Deanna Brown Thomas, Venisha Brown, Daryl Brown, Yamma Brown Lumar and Larry Brown.
Their lawyer, Louis Levenson, said the children had discovered earlier wills drafted by their father which cast doubt on whether he wanted most of his money left to charity.
"There was sporadic indication that Mr Brown intended to benefit some charities, but the circumstances surrounding the making of these documents have always been clouded in mystery," he said.
A sixth child named in Brown's will, Terry Brown, is using a different lawyer.
Brown died from pneumonia on Christmas Day 2006.