WASHINGTON (AP) — Leaders of the House Oversight Committee on Tuesday accused a prominent Washington law firm of trying to interfere with their investigation into use of personal email accounts by government officials.

Reps. Darrell Issa, R-Calif., and Elijah Cummings, D-Md., said they were outraged by an email sent by an employee at Dickstein Shapiro, a firm that represents Jonathan Silver, former head of the Energy Department’s loan program office.