The California Public Employees’ Retirement System said Winston, which represents a bond insurance creditor in the two cases, lured away members of its K&L Gates counsel in what the fund’s CEO called "a very serious case" of "side-switching."

"Winston has a serious conflict of interest resulting from its hiring members of CalPERS legal team while representing an adverse party," said Anne Stausboll, CalPERS’ chief executive officer said in a prepared statement. "CalPERS is acting swiftly to ensure the interests of our members are not compromised."