British oil major BP Plc. has accused oilfield services Haliburton Co. of destroying important test results related to the Deepwater Horizon explosion, according to various media reports.

The British oil company alleged that Halliburton destroyed tests results showing unreliable cement was used at the oil rig that resulted in the well's blowout, which caused an explosion that killed 11 workers and caused the region's worst environmental disaster, reported the Houston Chronicle on Monday.

In a 310-page legal filing, BP accused the Houston-based oil industry service company of refusing to relinquish test results and then destroying them.

Halliburton intentionally destroyed the evidence related to its non-privileged cement testing, in part because it wanted to eliminate any risk that this evidence would be used against it at trial, BP said in its filing, reported the Houston newspaper.

The accusation comes after BP claimed a Halliburton employee admitted under oath of destroying documents that company officials were afraid could be used against the company in court, reported the Dow Jones Newswires. The concrete tests were conducted in Oklahoma in May of 2010 and showed that solids separated from liquids, a direct sign that the concrete was low quality and unstable, reported the news service.

Halliburton representatives have called BP's filing and accusations groundless.

Halliburton in on Sept. 1 filed a defamation suit against BP for negligent misrepresentation and fraud. The company claimed BP did not fully disclose where the company found hydrocarbons in the Gulf and then failed to mention the omission during subsequent investigations into the spill.

Halliburton has learned that BP provided Halliburton inaccurate information about the actual location of hydrocarbon zones in the Macondo well, read a company release issued Sept. 2. The actual location of the hydrocarbon zones is critical information required prior to performing cementing services and is necessary to achieve desired cement placement.

Halliburton remains confident that all the work it performed with respect to the Macondo well was completed in accordance with BP's specifications for its well construction plan and instructions, and that Halliburton is fully indemnified under the contract, it said.