DOJ representatives could not be immediately reached for comment.
The DOJ investigation stemmed in part from PennPSERS staff discovering in 2020 that investment reporting figures for April 2015 that were used for an annual employer contribution rate increase contained a calculation error.
After the board was notified of the error, it commissioned in March 2021 a report from law firm Womble Bond Dickinson to assist the retirement system's chief counsel in investigating potential litigation from the risk-share calculation error.
The report, released in January, found no evidence of criminal conduct.
According to the report, general investment consultant Aon Investments USA took responsibility for the error, which involved incorrect public markets investment returns in April 2015 that was only discovered by PennPSERS staff in 2020 following Aon's release of nine-year investment return data.
"In the process of reconciling some prior year asset class composites … Aon has become aware of data corruption. … This data corruption impacted a few asset class composites in the public markets," Womble Bond's report said.
Matt D. Basil, partner at Willkie Farr & Gallagher, counsel for Aon, said in January that Aon disagrees with the findings of the report. According to the Womble Bond report, Aon would not agree to an interview for the report but provided answers to submitted questions.
Aon spokesman Robert Elfinger declined to comment, citing pending litigation.