Rihanna reportedly fired her business manager after discovering she only has $20,000 left in her bank account.
Patricia Williams claims she was recently "let go" after Rihanna accused her of stealing after discovering her pop fortune has all but disappeared.
Williams said: "It's not my fault that she only has $20,000 to her name. I have worked for many high-profile actors, musicians and multi-million dollar corporations. Why would I steal from Rihanna?"
"I showed her all the paperwork and tried to explain to her the circumstances but she wouldn't listen. She called me all sorts of horrible names and stormed off."
"I now feel compelled to share with the world the background story as I will not allow my name to be slandered."
Rihanna's recent album Good Girl Gone Bad has sold an estimated five million copies worldwide and she has toured extensively across the U.S. and Europe this year.
Williams claims the 20-year-old singer's record label Def Jam and her manger Marc Jordan are to blame for her financial problems.
She is quoted by website blackarazzi.com as saying: "Def Jam doesn't fund Rihanna properly, so Marc uses the money Rihanna makes from third-party endorsements and from tours to fund her album and music videos."
"I don't want to disrespect Marc's name. He is a fantastic manager and genuinely believes in Rihanna. But he uses her money to fund her future projects because he believes he can break her in the world-market. Her album sales are not nearly as close to her single sales and he knows that if she is only known as a 'singles artist' she will only be as good as her last hit. Unfortunately, he didn't inform his client and I'm receiving the brunt of it."