(Reuters) -The U.S. Federal Aviation Administration is investigating falsified documents that were used to verify the authenticity of titanium used in some recently manufactured Boeing ( BA ) and Airbus jets, the New York Times reported on Friday.

The falsified documents are being investigated by the FAA and Spirit AeroSystems ( SPR ), which is a supplier to both Boeing ( BA ) and Airbus, NYT said in the report citing a supplier for the planemakers.

The FAA, Boeing ( BA ), Airbus and Spirit did not immediately respond to Reuters' requests for comments.

The investigation comes after a parts supplier found small holes in the material used in manufacturing of jets from corrosion, the report added.