Rep. Darrell Issa (R-Calif.) has been forced to postpone a hearing on an inspector general’s investigation of “Operation Fast and Furious” until next week.

The Justice Department’s inspector general, Michael Horowitz, told Issa in a recent letter that after 17 months of investigating the botched gun-tracking operation, the lengthy report would not be ready for public release until later this week, at the earliest.

Issa, the chairman of the House Oversight and Government Reform Committee, worried the DOJ would try to delay the report’s release for political reasons, according to an earlier letter to Horowitz sent last month. And the powerful Republican was hoping to use Tuesday, Congress’s first full day back at work after its summer recess, to launch into the report’s findings as soon as possible.