A spokeswoman from Gate Gourmet, the Dutch caterer used by Delta, has said that the company is cooperating fully with investigators. Christina Ulosevich added that "details of this matter must remain confidential".
Gate Gourmet is a subsidiary of Swiss-based gategroup Holding AG, one of the largest independent global providers of airline passenger products and services.
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Expect a bright day today with plenty of winter sunshine and clear blue skies across the country.