Updated

WASHINGTON  -- The federal government's spill chief is considering whether to pump heavy mud and cement through BP's experimental well cap that's keeping oil from the Gulf of Mexico.

Retired U.S. Coast Guard Adm. Thad Allen says Tuesday that the procedure would make it easier to complete the permanent fix of plugging the oil from the bottom of the blown out well because the oil would be smashed in from two directions.

No oil would be released.

The mechanical cap has stopped the oil since Thursday. But several leaks had caused mounting concern that the cap was displacing pressure and causing leaks deep underground.