BP is accusing Halliburton of destroying damaging evidence about the quality of its cement that went into the Deepwater Horizon well that exploded, killing 11 people and causing America’s worst offshore oil spill.

Authorities took one man into custody on suspicion of arson and were searching for another after a wildfire in south-western Oklahoma destroyed at least 30 homes and forced the evacuation of two schools, a nursing home and businesses.