NEW YORK, U.S. - U.S. federal investigators are gearing up to file charges against a wider array of insider-trading networks, Bloomberg News reported on Sunday, citing people familiar with the matter.

Some of these charges are linked to the criminal case against billionaire hedge fund founder Raj Rajaratnam, the unidentified sources told Bloomberg.

The crackdown is based on at least two years of investigation and will target securities professionals such as hedge fund managers, lawyers and other Wall Street players, the news and financial information provider reported.

Some probes rely on wiretaps while others stem from a secret U.S. Securities and Exchange Commission (SEC) data-mining project set up to identify clusters of people who make similar well-timed stock investments, Bloomberg reported. Bloomberg said the SEC and the Justice Department declined to comment.

Officials with the SEC did not immediately respond to emailed requests for comment from Reuters.

Galleon Group founder Rajaratnam and executives from major American companies were charged on Friday with the largest hedge fund insider-trading scheme ever.

Six people were charged with securities fraud and conspiracy in two criminal complaints filed in U.S. District Court in Manhattan.