New York (CNN Business) Hundreds of 737 Max jets are sitting, grounded, as Boeing awaits approval from aviation regulators for the troubled plane to return to flight. But now, the company has discovered yet another potential hurdle.

The plane was grounded worldwide in March after two crashes that killed 346 people. The company determined a software fix was likely to correct the issue with the automatic safety feature that caused the crashes.

Boeing BA However, as part of a December audit of the plane's safety ordered by the US Federal Aviation Administration,found "previously unreported concerns" with wiring in the 737 Max, according to a report earlier Sunday from the New York Times . The company informed the FAA last month that it is looking into whether two sections of wiring that control the tail of the plane are too close together and could cause a short circuit — and potentially a crash, if pilots did not react appropriately -— the Times reported, citing a senior Boeing engineer and three people familiar with the matter.

A Boeing spokesperson confirmed the report to CNN Business on Sunday, saying the issue was identified as part of a "rigorous process" to ensure the plane's safety.

"Our highest priority is ensuring the 737 Max meets all safety and regulatory requirements before it returns to service," the spokesperson said. "We are working closely with the FAA and other regulators on a robust and thorough certification process to ensure a safe and compliant design."