Updated

A top Senate Democrat on Sunday joined the chorus of lawmakers vowing to get to the bottom of what happened in Vegas -- after a federal agency blew through more than $820,000 for a 2010 conference.

Sen. Dick Durbin, D-Ill., the No. 2 Democrat in the chamber, said the subcommittee he leads on the Senate Appropriations Committee will hold a hearing on the controversy when Congress returns from break.

"It's an absolutely outrageous expenditure of taxpayers' money," Durbin said on NBC's "Meet the Press." "That kind of misuse of taxpayers' funds is totally unacceptable."

The exploits of the Public Buildings Service, a chapter of the General Services Administration, have emerged as one of the few things Democrats and Republicans in Washington can agree on. Lawmakers of both parties have roundly condemned the conference spending, detailed in an inspector general's report last week, as over-the-top.

Two House committees already have launched their own investigations. One is trying to find out more about a separate incentive program that allegedly allocated $200,000 for iPods, gift cards and other rewards for employees.

The IG report detailed how conference organizers spent thousands of dollars on seemingly frivolous items, ranging from commemorative coins to souvenir yearbooks to a mind-reader, at the conference held just outside Las Vegas.

The scandal deepened later in the week, when video clips surfaced from the conference of federal employees joking about the lavish expenses.

The head of the GSA and two other officials resigned in the wake of the report, and Obama administration officials have condemned the actions of the agency.