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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One story dominates Thursday's front pages with some newspapers printing emotive pleas to voters to keep the United Kingdom as one.
After a mild start temperatures should pick up, with the south of England seeing highs of 26C.
In Edinburgh tonight you can hear it and feel it. The buzz, the banter of the day and the thrilling sense something big is coming tomorrow.