(CNN) - State Senator Jake Knotts, a Republican and longtime critic of Mark Sanford, called for a "full-blown" investigation Friday into the South Carolina governor's actions.
In a press conference with reporters, Knotts said he is actually calling for two investigations - one by the state's law enforcement agency, and the other by the State Senate Judiciary Committee with "full subpoena power."
"Irrational behavior. Lies, lies, lies. It's time that the truth to come out," said Knotts. "Like Joe Brown said, you can lie, but you can't hide... Everybody has found out where he's been hiding. In Argentina."
Knotts said he wants the investigation to focus on "the misappropriation of taxpayer money, malfeasance in office, misconduct in office and all the area surrounding the recent behavior concerning the governor's office." The investigation also would include the question of whether Sanford's office may have been deliberately misleading about the governor's whereabouts during his absence.
Knotts added he is not yet calling on Sanford to resign, but said the embattled governor is "in the fast lane to make that decision, along with numerous other legislators that I have talked to on the phone."
Later, in an interview with CNN, Knotts said he would take Sanford's resignation "in a heartbeat."