Missouri Gov. Eric Greitens

Attorneys for Gov. Eric Greteins' office want to be able to call and publicly question witnesses during a potential impeachment process in the Missouri House.

The man whose then-wife had an affair with Gov. Eric Greitens has been subpoenaed to testify before a St. Louis grand jury, the man's attorney said Monday.

Greitens met Thursday with Cabinet members and placed calls to rally support while his attorney issued firm denials to a smattering of allegations related to the affair.

Gov. Greitens acknowledges he was "unfaithful" in his marriage but denies allegations that he blackmailed the woman he had an extramarital affair with.