The FBI is investigating missing gas in Wilkes-Barre, the county District Attorney's Office confirmed Monday.

The United States Attorney's Office and the Luzerne County District Attorney's Office are conducting a joint investigation, said First Assistant District Attorney Sam Sanguedolce.

"We have encountered great difficulty in obtaining certain information with respect to the Wilkes-Barre gas investigation. As result of meetings with the U.S. Attorney's Office and the FBI, we believe a joint investigation is appropriate to obtain that information for both entities to review and make a determination as to whether charges warranted," he said.

The district attorney's office and federal investigators met several weeks ago. The DA's office shared about 500 pages of reports and attachments and interviews that county detectives conducted with at least 43 witnesses.

Sanguedolce said it was difficult to say when the investigation would conclude.

"It depends where the information leads, if anywhere," he said. "Because of the breadth of the operation, it's hard to say. If it leads to other avenues, it could take a while. If it's open and shut quickly, the answers could come out right away."

FBI spokeswoman Carrie Adamowski confirmed the bureau is involved in the investigation.

Amanda Endy, a spokeswoman for the U.S. Attorney's Office, wrote in an email that "The U. S. Attorney's office and the FBI have had communications with the Luzerne County District Attorney's office about the matter but we have no other comment at this time."

Wilkes-Barre spokeswoman Liza Prokop said city police told her the district attorney's office turned over the investigation to the FBI. She said the FBI had not requested information or interviews from anyone in the city regarding the gas investigation.

"Mayor Tom Leighton, on behalf of the City of Wilkes-Barre, will fully cooperate with any law enforcement and regulatory agency who is conducting any investigation as we have always done in the past," Prokop said in an emailed statement.

The district attorney's office began investigating gas missing from city pumps in July 2012. The city could not account for about 67,000 gallons of gas taken from municipal pumps between July 2010 and July 2012, according to an investigation by the Pennsylvania Department of Revenue. That agency fined the city about $26,000 for the missing gas.

bwellock@citizensvoice.com 570-821-2051, @CVBillW