A hedge fund executive has pleaded guilty and a former New York political leader plans to surrender on charges related to a state pension fund investigation.

Records unsealed Tuesday show Dallas-based Barrett Wissman pleaded guilty on 31 March to securities fraud. His lawyer says Wissman is cooperating. Ray Harding's lawyer says the former head of New York's Liberal party is surrendering Wednesday. The charges were not immediately known. Attorney David Frankel says Harding hasn't broken any laws.

The ongoing inquiry, which is examining the activities of a number of investment companies, focuses on what has been a widespread practice among hedge funds and private equity firms - paying so-called placement agents to gain business managing the pension funds run by states for public employees. Such payments often raise questions about conflicts of interest and concerns that they lead placement agents to bribe public officials.

The New York Attorney General's office confirmed Wednesday that Wissman, who was a managing director of HFV Asset Management LP and who worked for a time as a placement agent for Access Capital Partners, had entered a guilty plea in the case and declined further comment. The New York Times reported Wissman's guilty plea in its editions Wednesday. He is the first fund executive to plead guilty in the case.

Two of former Comptroller Alan Hevesi's aides were previously charged. They're accused of taking payments to steer billions of dollars in pension fund investments to favoured companies.

New York Attorney General Andrew Cuomo has alleged the men essentially sold access to billions of dollars in money held by the New York State Common Retirement Fund to favoured investment firms in exchange for kickbacks and other payments for personal and political gain.

The Securities and Exchange Commission also has brought a parallel civil case against the men, alleging in part that millions of dollars in sham finder or placement fees were paid to Hevesi aide Hank Morris from 2003 to 2006. Cuomo's office has alleged more than 20 investment deals involving the state pension fund that were tainted by the kickback scheme.

The deals included investments involving Aldus Equity Partners, which manages the NY/Emerging Fund LP for the Common Retirement Fund; Access Capital; Odyssey Investment Partners; a hedge fund and a private-equity fund associated with Art Samberg's Pequot Capital Management; and Strategic Co-Investment Partners LP, jointly managed by Pacific Corporate Group Capital Partners and Clinton Group Inc.

The Carlyle Group, which over the years has employed former US President George HW Bush and the former British Prime Minister John Major, is among the most prominent of the firms under scrutiny, and manages $1.5 billion of the state's pension assets. Carlyle's efforts to gain pension business in other states have drawn criticism before, but company officials have never been charged with any wrongdoing.