Texas prosecutors have apologized to a federal judge for their seizure of thousands of X-rays gathered from lawsuits across the country claiming lung injuries traced to industrial exposure to finely ground sand, known as silica.

In their eagerness to investigate what Judge Janis Jack of Corpus Christi described as widespread fraud in the silicosis litigation, attorneys working for the attorney general of Texas, Greg Abbott, used armed law enforcement officers to take the X-rays from a court-established depository in June. The state prosecutors said they acted pursuant to subpoenas signed by county judges, but the move angered Judge Jack, who said the action was unconstitutional and an affront to the jurisdiction of the federal courts.

“Not seeking prior leave of this court was an error, and for that, the office of the attorney general apologizes,” an associate deputy attorney general for litigation, David Morales, wrote in a letter to Judge Jack last week. “Internal miscommunication resulted in the senior attorneys who were supervising the investigation believing that approval of the court had been sought, when in fact it had not.”

However, even the office’s apology was marred with trouble when a court clerk refused to accept affidavits in which Mr. Abbott’s office detailed how the misunderstanding developed.

The prosecutors sought to file the affidavits under seal with the court and without providing copies to lawyers overseeing the silica-related litigation. Mr. Morales said the internal discussions were legally privileged and should be kept confidential, but a note that he scrawled at the end of his letter indicates that Judge Jack viewed the affidavits as an improper ex parte communication with the court. An inventory found 152 X-rays missing, but prosecutors have denied responsibility.