Updated

Federal prosecutors are appealing a judge's decision to grant a new trial to a former BP engineer convicted of obstructing justice in an investigation of the 2010 Gulf of Mexico oil spill.

The notice of appeal was filed in the case of Kurt Mix in federal courts Friday.

Prosecutors accused Mix of deleting text messages about the amount of oil flowing from BP's Macondo well after the Deepwater Horizon rig explosion.

U.S. District Judge Stanwood Duval threw out Mix's December 2013 conviction and granted a new trial. He ruled that a jury forewoman tainted the deliberations by mentioning to a deadlocked jury that she had heard something outside the trial that affirmed her view of Mix's guilt.