Source: Resigning US lawmaker under investigation by Justice

A person familiar with the case said that the US Justice Department is formally investigating whether a congressman, who has submitted his resignation, committed crimes with his office expenditures and business dealings.

The government is convening a federal jury in his home state of Illinois, this source tells The Associated Press, and the FBI has started issuing subpoenas to compel people close to the Republican Rep. Aaron Schock to testify. The source spoke only on grounds of anonymity because the person wasn't authorised to publicly discuss the case.

Schock, a rising star in the party, abruptly resigned earlier this week following a monthlong cascade of revelations about his business deals and lavish spending on everything from overseas travel to office decor in the style of "Downton Abbey.