The FBI is now probing Boeing and its controversial 737 MAX certification process, along with federal aviation investigators, a report says.

Sources told The Seattle Times on Wednesday that agents have started assisting the Department of Transportation with its ongoing inquiry, which is being overseen by the Justice Department’s criminal division and carried out by the DOT Inspector General.

Investigators have been looking into the Federal Aviation Administration’s approval of Boeing’s 737 MAX airplane — and in particular its anti-stall system — following this month’s deadly Ethiopian Airlines crash and the tragic Lion Air incident from last October.

The FAA reportedly certified the aircraft two years ago.

French investigators say they have analyzed data from both the Ethiopian and Lion Air crash and discovered “clear similarities” between the two incidents — which left everyone on both planes dead.

The 737 MAX 8 fleet has been indefinitely grounded in the wake of what happened.