BP accused Halliburton of having intentionally destroyed evidence about possible problems with its cement slurry poured into the deep-sea Macondo well about 100 miles (160 kilometres) off the Louisiana coast. An oil well must be cemented properly to avoid blowouts.
Also in the documents filed in a New Orleans federal court, BP accused Halliburton of failing to produce incriminating computer modeling evidence. BP accused Halliburton of claiming the modeling is gone.
BP asked U.S. District Judge Carl Barbier to penalize Halliburton and order a court-sponsored computer forensic team to recover the missing modeling results.
Halliburton did not return a call seeking comment but told other media outlets that the accusations were untrue.
The allegations in the 310-page motion ratcheted up the showdown among BP PLC and contractors, Halliburton and Transocean Ltd. The three companies have been sparring over blame for the April 2010 Deepwater Horizon blast, which killed 11 workers and led to the release of 206 million gallons (780 million litres)of crude oil into the Gulf of Mexico. So far, BP, the majority owner of the Macondo well, has footed the bill for the emergency response and cleanup.
Also involved are Anadarko Petroleum Co. and Cameron International Corp.
The first trial over the Deepwater Horizon disaster is scheduled to start Feb. 27 in New Orleans. The first leg is expected to take about three months and determine the liability of each company involved in drilling the Macondo well. There will be other phases over cleanup costs, punitive damages and other claims.
Federal and independent investigations of the disaster have found fault in Halliburton's cement job because it failed to properly plug the well. Halliburton used a foamy cement slurry.
In Monday's court filing, BP accused Halliburton employees doing an internal investigation of the Macondo disaster of discarding and destroying early test results they performed on the same batch of cement slurry used in the Macondo well.
BP said Halliburton's chief cement mixer for Gulf projects testified in depositions that the cement slurry seemed "thin" to him but that he chose not to write about his findings to his bosses out of fear he would be misinterpreted.
"I didn't want to put anything on an email that could be twisted, and turned," Rickey Morgan, the Halliburton cement expert, said in depositions. He worked at a laboratory in Duncan, Oklahoma.
"Upon reviewing these latest testing results, Halliburton employees destroyed records of the testing as well as the physical cement samples used in the testing," BP alleged.