Two years ago, as New Jersey Gov. Chris Christie pursued re-election, his administration found itself mulling investment options for the state’s $80 billion pension fund. In one deal in May 2013, officials settled on a subsidiary of U.K.-based foreign financial conglomerate Prudential plc. With little fanfare, state pension overseers quickly endorsed the deal.

Weeks later, a Hong Kong-based executive director and board member of Prudential plc delivered a maximum $3,800 contribution to Christie’s gubernatorial campaign, followed by a maximum $32,400 donation to the Republican National Committee, which was about to launch a get-out-the-vote effort for Christie. Two months after that, New Jersey began moving public employees’ retirement savings into two funds managed by the Prudential subsidiary as part of the state’s new $300 million investment commitment to the company.

State and federal rules are designed to prevent firms that manage public pension money from contributing to the campaigns of public officials who have the authority to influence pension investments. The sequence of transactions in New Jersey, campaign finance experts say, is troubling.

"Pay-to-play laws are intended to stop the potential conflicts of interest and appearance of corruption that arises whenever executives at a financial firm make large political contributions to a governor and his political party around the time the state is picking the firm to handle pension system investments," said Larry Noble, a former general counsel of the Federal Election Commission who now works for the nonpartisan Campaign Legal Center, a research group in Washington, D.C. "These situations undermine the public’s confidence in the integrity of government contracting."

Prudential plc said the donations from Barry Stowe, one of the firm's executive directors, were in no way improper.