Congressional lawmakers grilled General Services Administration officials for a third straight day Wednesday about a rogue employee’s penchant for lavish, taxpayer-funded junkets, unearthing evidence that the waste, fraud and abuse is more common and has been going on much longer than first indicated.

Over the last six years, the GSA, which is in charge of the federal government’s real estate holdings, has been racked repeatedly by financial kickbacks, insider dealing and general incompetence, lawmakers said.