NEW YORK (Bloomberg) — US prosecutors interviewed former American International Group Inc. executive Joseph Cassano and are to continue today as they weigh whether to bring criminal charges related to the insurer's collapse, according to a person familiar with the discussions.

The Washington interview of Cassano, the former chief executive officer of AIG's Financial Products division, came as prosecutors wrap up a probe into whether AIG executives misled investors and auditors about sub-prime mortgage-related losses, according to the person, who declined to be identified because the talks are confidential.

The Justice Department and the Securities and Exchange Commission, which the person said participated in the talks, are examining statements by AIG executives in 2007. Investigators are focusing on comments made about the company's portfolio of "super senior" credit-default swaps, which insured bond losses tied to the US housing market. Losses on the credit-default swaps helped lead to the $182.3 billion taxpayer bailout of New York-based AIG that gave the government a majority stake.

Department of Justice spokeswoman Laura Sweeney and SEC spokesman John Nester today declined to comment. Cassano attorney Joseph Warin of Gibson Dunn & Crutcher LLP in Washington didn't immediately return a call after business hours. Warin previously said Cassano was cooperating with investigators and acted lawfully.

Cassano, 55, hasn't been charged with any wrongdoing.

Lawyers for individuals who may be the subject of a criminal investigation rarely allow the government to talk to their clients unless there is an assurance of immunity related to the information provided, former federal prosecutor Peter Zeidenberg said. If a person is later charged with a crime, prosecutors may use those statements to cross-examine the defendant if he denies what he previously told them.

"It's customary for defence attorneys to have a subject or a target of an investigation who is coming in for an interview to sign a so-called 'queen for a day,' agreement," said Zeidenberg, a lawyer with DLA Piper LLP in Washington. "The client may feel that there's an innocent explanation for their conduct and, once the government understands that, they won't pursue them further."