Published: Mar 05, 2011 3:59 AM EST
Updated: Mar 05, 2011 12:59 AM EST

NEW ORLEANS (AP) - There may have been a fundamental safety design problem with the pods that controlled the massive device that failed to stop the Gulf oil spill, federal investigators said Friday as they asked that more testing be done to confirm that.

The U.S. Chemical Safety Board has objected to the government's decision to halt testing of the blowout preventer on Friday.

The Associated Press obtained a copy of a letter the board sent to the team that has been overseeing the testing since November at a NASA facility in New Orleans. The team is jointly run by the U.S. Coast Guard and the Bureau of Ocean Energy Management Regulation and Enforcement.

The safety board has been among the groups allowed to monitor the testing.

The Norwegian firm doing the testing, Det Norske Veritas, is expected to submit its findings by March 20.

A spokeswoman for the joint investigation team, Melissa Schwartz, said in an e-mail to the AP that the scope of the work done by DNV was developed in coordination with other interested parties, including the safety board, and in consultation with the Justice Department. She said there have been no other objections.

She said the team believes DNV has performed the tests necessary to determine why the blowout preventer did not function as intended.

Cameron, the company that made the blowout preventer used with BP's blown-out well, had no comment, according to a spokeswoman.

Blowout preventers sit at the wellhead of exploratory wells and are supposed to lock in place to prevent a spill in case of an explosion.

The 300-ton device that was used with BP's Macondo well was raised from the seafloor on Sept. 4. It sat at the NASA facility for two months before testing began.

The USCG-BOEMRE panel recently said that it won't finish its final report on what caused the April 20, 2010, rig explosion and oil spill in the Gulf of Mexico by the one-year anniversary of the disaster as it had hoped.

Delays in testing the blowout preventer forced the panel to seek another deadline extension.

Its final report was due this month. Instead, the panel now has until July. It will make a preliminary statement by mid-April.

(Copyright 2011 by The Associated Press.  All Rights Reserved.)