IRS Commissioner John Koskinen, testifying before a House oversight subcommittee, stressed that he does not know “how they found them” or “whether there’s anything on them or not.” But he said the inspector general’s office advised him the investigators are reviewing tapes to see if they contain any “recoverable” material.

The revelation is significant because the IRS claimed, when the agency first told Congress about the missing emails, that backup tapes “no longer exist because they have been recycled.”

It is unclear whether the tapes in IG custody contain any Lerner emails, but Koskinen said investigators are now checking.