The legal battle over last year's oil spill in the Gulf of Mexico is turning increasingly bitter. Thus, the Financial Times is today reporting on British Petroleum (BP) allegations that Halliburton, the company which provided the concrete for the Deep Water Horizon rig, has "destroyed test results and computer analysis" to reduce the risk of having the potentially damaging evidence presented at trial.The accusation is contained in papers submitted to the New Orleans Court which will hear the trial for damages resulting from the spill which nearly destroyed BP and saw its chief executive Tony Hayward resign.Halliburton says the accusations are "without merit". BP's shareprice has been flat in morning trading, Halliburton rose 1.2% yesterday in New York.BS