The probe stems from a legal wrangle over the Feb. 7, 2008, explosions and fire at the company's refinery near
Investigators have said that disaster - which killed 14 people and hurt many others who were treated at Augusta's Joseph M. Still Burn Center - and the Sugar Land mishap were fueled by big buildups of sugar dust.
Now, lawyers for the Department of Labor's Office of the Solicitor are gathering information concerning the Texas explosion.
They also are pressing the government's case for $8.8 million in fines for more than 200 alleged safety violations at Port Wentworth and the company plant in Gramercy, La.
Imperial is appealing.