Missouri lawmakers returned to the Statehouse Monday for the first time since Gov. Eric Greitens was indicted, with plans to discuss assembling a committee whose investigation could lead to his impeachment.

The first-term Republican governor was indicted late Thursday by a St. Louis grand jury on felony invasion of privacy. The charge stems from an extramarital affair he had with his hairdresser in March 2015, before he was elected.

Prosecutors allege Greitens took a compromising photo of the woman without her consent. Greitens has admitted to the affair but said no crime was committed. His attorneys have requested that the indictment be dismissed.

House Republican leaders said last week they'll form a group of lawmakers to investigate the allegations and determine whether the governor can lead the state amid the felony case. Greitens' attorney said he welcomes the investigation.

House leaders didn't specifically mention impeachment, a process that must begin in the House with an investigation. Several lawmakers, including some Republicans, have questioned whether Greitens can continue to effectively lead.

Meanwhile, the grand jury investigation of Greitens is "ongoing," said Susan Ryan, a spokeswoman for St. Louis Circuit Attorney Kim Gardner. She declined to say what the grand jury is looking into, or when it might wrap up.

On Sunday, the attorney for a man convicted of invasion of privacy in St. Louis 19 years ago asked Greitens for a pardon, using the same argument that the governor's lawyers are using in the effort to dismiss the Greitens indictment.

In 1999, Paul Henreid, who now lives in California, was convicted of felony invasion of privacy in St. Louis. Henreid's attorney, Al Watkins, said it would be "hypocritical" for Greitens to reject the pardon request. A message left Monday with Greitens' spokesman was not immediately returned.

Henreid's trial attorneys argued that the law was aimed at "peeping Toms," not someone engaged in a consensual relationship. Greitens' attorneys made a similar argument in the motion to dismiss.

Watkins also represents the ex-husband of the woman who had the affair with Greitens.

Greitens' whereabouts on Monday were uncertain. Briden did not respond to multiple messages seeking information about where Greitens was or what he was doing.

About 100 protesters gathered Monday outside a St. Louis courthouse to show support for Gardner after Greitens issued a statement last week alleging that the indictment was politically motivated. The statement referred to Gardner, a Democrat, as a "reckless liberal prosecutor."

The Rev. Darryl Gray, one of the protest leaders, said the statement by Greitens had racial undertones.

"Any time you have black leadership that stands up and challenges the status quo, the first thing that comes is character assassination," Gray said.