NEW ORLEANS (AP) -- A former BP (NYSE:BP) engineer charged with deleting text messages about the company's response to its 2010 oil spill in the Gulf of Mexico says federal prosecutors have tacked on "farcical" allegations that he also deleted dozens of voicemails.

A court filing Wednesday by Kurt Mix's defense attorneys asks a judge to bar prosecutors from making any references to nearly 350 voicemails that couldn't be recovered from Mix's phone.

Mix's lawyers also want copies of transcripts for the grand jury proceedings that produced a new March 20 indictment against their client. The new indictment added allegations that Mix deleted about 40 voice mails from a supervisor and roughly 15 voice mails from a BP contractor.

Mix, a resident of Katy, Texas, pleaded not guilty last May to two counts of obstruction of justice.

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