HOUSTON (Reuters) - A U.S. industrial accident investigative board served Black Elk Energy with a subpoena on Monday, seeking information about last week's offshore Gulf of Mexico oil platform explosion that left one worker dead and another missing.

Spokeswoman Hillary Cohen said the U.S. Chemical Safety and Hazard Investigation Board, which investigates chemical spills, refinery explosions and other industrial accidents, will decide whether to launch a probe into Friday's blast once Houston-based Black Elk responds to the subpoena.

The company has until November 30 to respond, Cohen said. The CSB has authority to subpoena witnesses, but not to issue fines or citations.

The U.S. Bureau of Safety and Environmental Enforcement (BSEE), which regulates offshore oil and gas drilling and production, is investigating the blast.

BSEE said on Monday that its investigative team met Black Elk personnel at the platform to go over the agency's plan to collect evidence, interview witnesses and review safety procedures.

Once that information is analyzed, the agency can decide what enforcement plans are appropriate, BSEE Director James Watson said.

On Saturday one of two missing workers was found dead and the U.S. Coast Guard suspended search and rescue efforts. Privately held Black Elk said it expanded its search for the second missing worker.

On Monday, Black Elk did not respond to multiple queries about the status of the search. The Jefferson Parish Coroner's office, where the body of the deceased worker was taken on Saturday, said on Monday it had not received a second body related to the blast.

Both those workers and several others hurt in the blast, are Filipino. Ambassador Jose Cuisa Jr. of the Philippine Embassy in Washington went to Louisiana on Monday to attend to the deceased man's remains, monitor the search and help the families of those injured. Continued...