ALBANY — The feds filed new charges in Albany yesterday against a Boston-based investor who they say targeted the state comptroller’s office’s top lawyer in a sex-related extortion plot for $35 million in pension-fund business.

Federal prosecutors from New York’s Northern District say Giridhar Sekhar, a former partner at F.A. Technology Ventures, threatened in e-mails to Comptroller Thomas DiNapoli’s general counsel last year to disclose an alleged extramarital affair by the attorney.

The general counsel, Luke Bierman, had spiked a $35 million investment deal between F.A. Technology and the state’s $133 billion retirement fund.

Albany County District Attorney David Soares recently abandoned a similar case against Sekhar after several charges were dismissed and the feds decided to pursue their own prosecution.