A criminal investigation of American International Group ( AIG) is focusing on at least three individuals who "may have misled the company's auditors and investors about the value of derivatives the firms sold," according to a report in The Wall Street Journal Tuesday.

The inquiry by the Justice Department and Securities and Exchange Commission is focusing on Joseph Cassano, who was in charge of AIG's Financial Products division, and Andrew Forster, another senior executive in that business who, like Cassano, was based in London. The third employee, Tom Athan, worked for the same division but was based in Connecticut, the article states.

Cassano left AIG last year, while the others remain at the company. They were among those who received controversial retention bonuses, but both men have agreed to give them back, the article states.

The men haven't been charged with wrongdoing, according to the report.