A former expert witness for indicted class action law firm Milberg LLP and other firms pleaded guilty on Thursday in Philadelphia to lying to judges about secret payments he got from the firms, prosecutors said. John Torkelsen, 62, provided evidence for plaintiffs about damages and settlement values in hundreds of class action and shareholder derivative lawsuits through his two companies, Princeton Venture Research Inc and Equity Valuation Advisors Inc. between 1985 and 2003.

Torkelsen, who is in federal custody awaiting sentencing on an unrelated case, pleaded guilty to one count of perjury in connection with a 1999 declaration to a San Jose federal court, according to U.S. prosecutors in Philadelphia. He faces up to five years in prison on the charge, and is set to be sentenced on Aug. 5. An attorney for Torkelsen was not immediately available for comment.

Prosecutors said the law firms told courts and class members that Torkelsen was being paid as an independent expert but secretly paid him a share of the proceeds of the cases.