The GSA’s 2010 Las Vegas conference cost the federal government $823,000. (Isaac Brekken/AP)

Robert Peck said in a letter to staff member Jeff Neely last summer that he found the four-day training conference’s general sessions “to be creative and professional presentations on important issues that we deal with in the Public Buildings Service.” He added that the event, held for 300 managers and staff at a luxury hotel that October, “appears to have been an effective means of informing the attendees about [Public Buildings Service] programs and policies and of facilitating an exchange of best business practices.” The tab for the conference was $823,000.

Peck then referred to an earlier briefing last May by the GSA inspector general, who was investigating the conference and issued a highly critical final report last week.

“Given that you had executive oversight of this [conference’s] planning and execution, you could and should have exercised better judgement concerning these expenditures,” Peck concluded in the letter. “You have served GSA as a senior manager long and well. This instance appears to reflect a managerial lapse which I expect will not be repeated.”

Martha Johnson resigned this month as head of the General Services Administration in the wake of a scandal over an agency spending spree in Las Vegas in 2010. (Michelle Farrell/via Bloomberg)

The letter was released Friday by the office of Rep. Darrell Issa (R-Calif.), chairman of the House Committee on Oversight and Government Reform. On Monday, Issa is to convene the first of four congressional hearings on the spending scandal. Peck, a fixture in the Washington area real estate community who was in his second stint at GSA, is expected to testify on Tuesday about his conduct surrounding the “Western Regions” conference.

Peck did not immediately respond to requests for comment on Friday.

The inspector general’s final report on the event, released last week, gave a harsh assessment of what took place during the conference. Included on the report’s list of questionable spending were $75,000 for a “team-building” exercise, $146,000 on food and drinks and $31,208 for the “networking” reception.

The scandal prompted the resignation of Johnson and the firing of Peck and another senior adviser to Johnson. Five top managers, including Neely, the acting chief of GSA’s Pacific Rim operation, have been placed on administrative leave.

Peck’s reprimand to Neely was strongly condemned by the agency deputy administrator who first reported the abuses to the inspector general.

In an e-mail in July 2011, also released Friday by Issa, Susan Brita told Peck that his letter to Neely “should have been crafted” while considering what a Washington Post story would say about the conference.

“If this story of GSA (federal workers) spending “almost a million dollars” (and I have no doubt that is how the Post would report the event) at a time of high unemployment, and down economy were to hit the press what would public reaction be, what would congressional reaction be, and how would the agency respond (especially the political leadership)?” Brita wrote. “Jeff is a seasoned SES who is expected to display the highest standards of common sense, and prudent financial management. He did neither. Sorry, but your letter is not even a slap on the wrist.”

Peck also is under scrutiny for organizing and hosting a private reception at the conference in his loft suite.

In an Oct. 26, 2010, e-mail to Neely, Peck invited top managers in attendance to an impromptu reception. He asked Neely to invite 80 managers.

“I’m only going to have limited refreshments, or I’d just throw the doors open to everyone here. Need to hold it to about 80 folks,” he wrote.

Peck charged $2,094 for food and drinks, according to an in-room dining receipt obtained by The Washington Post.