British oil giant BP said Wednesday it suspended the operation of an oil containment cap in the Gulf of Mexico after a discharge of liquids was observed.

Gas and oil continue to leak at the Deepwater Horizon oil spill site in the Gulf of Mexico in this frame grab captured from a BP live video feed June 22, 2010. The White House is set to step up its legal battle to keep deepwater drilling on hold in the Gulf of Mexico after oil companies persuaded a U.S. judge to overturn a six-month ban. Interior Secretary Ken Salazar said late on Tuesday he would order a new moratorium "in the coming days" to reinstate a temporary ban aimed at ensuring offshore safety after the worst oil spill in U.S. history struck at a BP operation on April 20. Picture taken June 22, 2010. [Xinhua]

Liquids were found running away at about 8:45 am Wednesday from a diverter valve on the drillship Discoverer Enterprise, which is on station over the leaking underwater well, BP said in a press release.

"As a precautionary measure, the lower marine riser package ( LMRP) containment cap system, attached to the Discoverer Enterprise, has been moved off the Deepwater Horizon's failed blow- out preventer (BOP) to ensure the safety of operations and allow the unexpected release of liquids to be analyzed," the company said.

As the containment system stopped work until the cap can be re- installed, BP said that a second containment system continued capturing oil and gas in the Gulf of Mexico.

U.S. Coast Guard Admiral Thad Allen, the government's national commander for the oil spill, said at a press conference in Washington that BP removed the containment cap because an underwater remote-operated vehicle (ROV) collided with it.

The ROV accidentally closed a vent on the cap, disrupting the system that funnels oil to the drillship Discoverer Enterprise, said Allen, adding that the closed vent forced gas into lines used to heat the system to prevent slush-like gas hydrates from plugging the cap.

However, Allen said, oil is not spilling "unconstrained" because it continues to flow to the Gulf surface through a second containment system.