The former business manager for Alanis Morissette has admitted embezzling millions of pounds from the singer and other celebrities.
Jonathan Schwartz, 48, of Los Angeles, agreed to plead guilty to federal charges, prosecutors said.
He was charged with wire fraud and filing a false tax return for failing to report the embezzled funds.
Schwartz admitted stealing nearly 5 million dollars (€4.7m) from Morissette between May 2010 and January 2014.
He used the money personally and falsely listed the cash withdrawals as "sundry/personal expenses" to cover up the crime.
When confronted about the theft, Schwartz lied and said he invested the money in an illegal marijuana growing business, prosecutors said.
Schwartz also admitted to stealing 2.3 million dollars (€2.16m) from five other clients who were not named in court documents or disclosed by lawyers in the case.
Defence lawyer Nathan Hochman said Schwartz had fully co-operated with investigators and accepted responsibility.
His plea deal calls for a sentence between four and six years in prison, though a judge could sentence him up to 23 years on the charges.
Schwartz had offered financial guidance to some of the biggest stars while working at GSO Business Management, a firm that touts its relationship on its website with entertainers such as Katy Perry, 50 Cent and Tom Petty.
Schwartz, who no longer works there, was said to represent Beyonce and Mariah Carey, who both appeared at a fundraiser last year in support of a heart disease charity he founded.
The embezzlement was discovered after Morissette took her business elsewhere and her new money manager discovered millions of dollars missing and contacted GSO, according to lawsuits filed against Schwartz.
GSO reviewed Schwartz's other work and found the other thefts, said GSO lawyer Chris Reeder, who sued Schwartz after he was removed from the firm.
"This was shocking and disappointing," Mr Reeder said.
"The company is very happy he's being brought to justice and held accountable for his actions."
Mr Reeder said GSO has since repaid all the money he stole from clients.
The firm's pending lawsuit against Schwartz said he used the money to fuel a lavish lifestyle that included a 50,000 dollar (€47,000) trip to the South Pacific island of Bora Bora and a 75,000 dollar (€69,000) debt at a Bahamas casino.
Morissette settled her suit against Schwartz and the firm, according to a joint statement issued last year.
Schwartz is scheduled to appear on February 1 in US District Court on the criminal charges.