WASHINGTON (AP) — As Congress investigates an $823,000 General Services Administration conference at a Las Vegas resort, a fired GSA executive who threw a party there on the taxpayers' dime has been sent a letter by his former agency demanding $1,960 reimbursement for the party in his room.

Robert Peck was set to testify in the second day of hearings before the House Transportation and Infrastructure Committee on the agency's misuse of taxpayers' money. Peck was commissioner of the Public Buildings Service at the GSA, which is in charge of federal buildings and supplies.

Another witness, current Deputy Commissioner Susan Brita, was instrumental in asking Inspector General Brian Miller to investigate the 2010 conference. His stinging report was made public April 2. Since then, the agency head resigned, two deputies, including Peck, were fired and 10 employees have been placed on administrative leave.

Brita had emailed Peck in July that the inspector general found no substantive agenda for the Las Vegas conference. She said expenses for a clown suit, bicycles used for a team-building exercise, tuxedos and a mind-reader didn't lend themselves to the claim of a substantive conference.

Brita also questioned why a regional administrator in charge of the conference, Jeffrey Neely, received only a disciplinary letter that "is not even a slap on the wrist."

Neely on Monday asserted his right to remain silent at a hearing before the House Oversight and Government Reform Committee.

At Monday's hearing, Miller, the inspector general, revealed he's investigating possible bribery and kickbacks and already has recommended criminal charges to the Justice Department.

"We do have other ongoing investigations including all sorts of improprieties, including bribes, possibly kickbacks, but I'd have to check on precisely kickbacks," Miller told the committee.

He added later, "We have recommended criminal charges."

Toward the end of the 3-1/2 hour hearing, GSA chief of staff Michael Robertson said he had informed the White House of the inspector general's preliminary findings last year. Robertson testified that he told a White House lawyer, Kim Harris, about the report shortly after May 2011 "when I became aware that the IG had briefed (then-GSA administrator Martha) Johnson."

After the hearing, Robertson said in a statement, "To clarify the point I made in my testimony today, I only mentioned in passing the existence of an IG investigation as I bumped into a White House staffer that I regularly worked with on GSA issues."

Committee members from both parties could barely restrain themselves as they sometimes shouted their outrage over the spending. They not only raged on about the overall figure, but at specific taxpayer expenditures for a mind-reader, overpriced commemorative coins, bicycles for a team-building exercise, and trips by GSA employees and their family members to the Las Vegas Strip.

Lawmakers said they couldn't understand why Johnson, the agency head who resigned after Miller's findings became public, waited for months to take action after receiving a preliminary report almost a year earlier. And they demanded to know why Johnson granted Neely a $9,000 bonus after learning of the conference.

"I gave that $9,000 bonus because I was focused on performance and because ... the recommendation came from the buildings commissioner," Johnson said.

Johnson, who said she resigned to allow the GSA to fix its problems under new leadership, said she was "extremely aggrieved by the gall of a handful of people to misuse federal tax dollars, twist contracting rules and defile the great name of the General Services Administration."

She said she learned after taking office that the Western Regions Conference "had evolved into a raucous, extravagant, arrogant, self-congratulatory event."