A spokesman for the EPA's Office of Inspector General told CNN that ongoing or pending reviews of Scott Pruitt will continue, even though he has resigned.

"Any ongoing or pending OIG reviews related to the Administrator and/or his team will continue—regardless of the administrator’s resignation," the spokesman said.

What we know about the investigation

The EPA inspector general is reviewing all of Pruitt's 2017 travel, which is expected to include multiple taxpayer-funded weekend trips that Pruitt took to Oklahoma, as well as official travel to Italy and Morocco.

The inspector general told Congress in a May 2018 letter that he expects the review will be completed by the end of September.

A different EPA inspector general review involves Pruitt's travel practices, suggesting that it will review Pruitt's use of his round-the-clock security detail, which travels with him even when off-duty on family vacations.

Both the EPA inspector general and the Government Accountability Office (GAO) are reviewing an April 2017 meeting that Pruitt had with the National Mining Association regarding the Paris climate agreement, which critics said may have violated anti-lobbying laws