Boeing voluntarily disclosed to the Federal Aviation Administration that it had procured titanium through a distributor who may have provided false or incorrect records, the FAA said Friday.

The New York Times reported earlier Friday that the FAA was looking into the use of counterfeit titanium from China in Boeing and Airbus jets.

“The FAA is investigating the scope and impact of the issue through our Continued Operational Safety process,” the FAA said in a statement to Spectrum News.

Boeing has issued a bulletin for suppliers outlining ways they should remain alert to potentially falsified records, according to the agency.

According to the New York Times, a supplier for the plane manufacturers raised concerns about aircraft structural integrity. The supplier said it had found holes in the titanium that had corroded.

Boeing is the subject of several ongoing investigations following a Jan. 5 incident involving one of its 737-9 MAX planes operated by Alaska Airlines, which experienced a midair blowout of a door plug. The National Transportation Safety Board and FAA currently have open investigations into the company.

On Thursday, Boeing said it is checking the fasteners on some of its 787 Dreamliner planes under construction to ensure they meet engineering specifications, following reports that some of the fasteners had not been installed correctly.

In May, the FAA opened an investigation into Boeing’s 787 Dreamliner, after the Seattle-based plane maker informed the agency it may not have completed required inspections to confirm adequate bonding and grounding where the wings join the fuselage on certain planes.

The FAA is looking into whether Boeing completed the necessary inspections and to see if employees falsified aircraft records. Last month, Boeing said it was reinspecting all of its Dreamliners in production and would create a plan to address the 787s that were in operation.