Residents found the drone on Sept. 1 near the village of Viișoara, roughly 30 kilometers (about 19 miles) from the border with Moldova.
After the discovery, the area around the crash site was cordoned off. A bomb disposal team from Romania's Intelligence Service (SRI) arrived at the scene to examine the drone.
According to preliminary information from security services, the device may have contained explosives. It remains unclear who owns the drone or under what circumstances it ended up on Romanian territory.
No casualties were reported as a result of the drone's crash, and no property damage was recorded.
The probe into the incident will be handled by the prosecutor's office at the Iași Court of Appeal. Law enforcement officials are expected to determine the drone's origin and the circumstances of its crash.
The night before, overnight into Sept. 1, Romania issued an air raid alert and scrambled aircraft over the threat of airspace violations during Russian strikes on southern Ukraine's Odesa Oblast.
Also on Sept. 1, Russian attack drones struck the Orlivka ferry crossing on the Ukrainian-Romanian border, temporarily halting its operations.