BP has accused the oil field services group, Halliburton, of destroying evidence relating to the oil well explosion in the Gulf of Mexico last year.
Eleven people died after the explosion and about four million barrels of oil leaked into the Gulf.
At a court hearing in New Orleans, BP said Halliburton had "intentionally" destroyed test results on the cement used at the Macondo well.
Halliburton denied this, saying the claims were "without merit".
Cement was a key factor in causing the oil spill. The blast that followed at the Deepwater Horizon oil rig on 20 April led to the release of 780 million litres of crude oil in the Gulf of Mexico.
The BBC reports the two companies are to go to trial over damages in the New Year. BP made its accusations in a court filing on Monday.
It said that after reviewing the test results, Halliburton "destroyed records of the testing as well as the physical cement samples used in the testing".
BP also said that Halliburton had failed to produce computer modelling evidence, which showed how the cement performed.
BP has asked for sanctions against Halliburton, claiming that the company's cement slurry was "unstable".
The BBC reports the trial is expected to apportion blame and quantify damages arising from the spill.