Four Congressional committees are planning to grill current and former General Services Administration officials this week about a lavish Las Vegas conference held in 2010, even as details continue to emerge about the agency’s spending habits.

New documents obtained by Roll Call show the GSA’s Region 9 headquarters in San Francisco, which organized the now-infamous Las Vegas conference, owns a facility suitable for a conference but spent hundreds of thousands of dollars renting out hotels and other venues for business meetings in the city.

The GSA booked the other venues because if it used its facility, “some people would be distracted” and “run up to their offices,” a GSA employee told the agency’s Office of Inspector General, according to an interview transcript. The employee said the agency spent $220,000 booking hotels for the business meetings rather than using its own facility.

House Oversight and Government Reform Chairman Darrell Issa (R-Calif.) will begin the oversight pile-on at 1:30 p.m. Monday. Witnesses at the hearing include Martha Johnson, the former GSA administrator who resigned in the wake of the OIG report; Jeff Neely, the regional commissioner who ran the San Francisco office and helped organize the conference; and Michael Robertson, the GSA chief of staff.

Rep. John Mica (R-Fla.), chairman of the House Transportation and Infrastructure Committee, which has jurisdiction over the GSA, is holding a hearing Tuesday.

On the Senate side, Mica’s counterpart, Environment and Public Works Chairman Barbara Boxer (D-Calif.), has scheduled a Wednesday hearing about the scandal. Senate Majority Whip Dick Durbin (D-Ill.), chairman of the Appropriations Subcommittee on Financial Services and General Government, is holding a hearing on the topic on Wednesday as well.

The hearings unfold as the GSA faces more bad news — the OIG this week referred the matter to the Department of Justice for possible criminal prosecution. That news, confirmed by Roll Call, was first reported by the Federal Times.

House Republicans said Friday that Neely received a $9,000 bonus last summer, a period during which the Las Vegas conference, as well as a separate program headed by Neely, was under investigation.

In an email to superiors reviewed by Roll Call, Neely said he “expect[ed]” to receive a score of 4 out of 5 from a performance review board and the bonus that came with it.

“I think the regions [sic] 2011 performance was pretty amazing,” Neely wrote.

Robertson, the agency’s chief of staff, could also be of particular interest to Republicans presiding over the committee because he previously served as legislative coordinator for then-Sen. Barack Obama (D-Ill.).

The OIG initially revealed in an April 2 report that the agency spent about $823,000 on an October 2010 Las Vegas conference for about 300 people, along with a series of colorful expenses that drove up the cost.

After the revelation, Johnson resigned, two of her top aides were fired, and four other managers were placed on leave.

According to documents obtained by Roll Call, GSA officials invented awards as an excuse to hold taxpayer-funded dinner events at conferences.

At one such event, the agency bestowed the “jackass award” on an employee, a GSA employee told the OIG, according to an interview transcript.

In the transcript, a GSA employee who attended the Las Vegas conference said officials routinely created awards to justify taxpayer reimbursement for dinner events.

“Typically at any — any conference in my memory over the last three or four years, probably even further back, there was always — there’s always one night where we have an awards ceremony and people are fed,” the employee said.

Describing the award ceremonies as a “running joke,” the employee said supervisors explained that the fake awards were designed to justify dinner events at the conferences.

“He says: ‘OK, everybody, just remember, the only way we can have food is if we have an awards ceremony.’ Maybe not in those exact words, but fairly similar,” the employee said.

At one conference, “I just remember one year like someone got like the jackass award or something for doing something stupid,” the employee said.

“The jackass award got everybody food?” the inspector general asked.

“Oh, yeah,” the employee said.

House Republicans say the “jackass award” and other revelations in interviews conducted by the inspector general show that the problem is deeper than the Las Vegas conference.

“GSA has been using tax dollars as a slush fund to pay for lavish parties and exotic vacations. From what we’re learning, GSA has a whole laundry list of instances where they were abusing taxpayer dollars. This goes a lot farther and a lot deeper than what we’ve seen,” said Rep. Jeff Denham (R-Calif.), chairman of a Transportation and Infrastructure subcommittee with jurisdiction over the GSA.

Dan Tangherlini, acting director of the GSA, issued an April 10 message via video that the expenditures at the conference were “completely unacceptable.”

“I speak for the overwhelming majority of GSA staff when I say that we are shocked and deeply disappointed by these indefensible actions,” Tangherlini said, outlining several steps the agency is taking to ensure wasteful spending at conferences does not happen again.