US halts BP oil cap tests in 'abundance of caution'

The US government has halted a series of tests by BP on the leaking well in the Gulf of Mexico, for fear that they may cause more damage.

Officials fear that closing the valves on the new cap could cause a build up of pressure, threatening a new rupture.

White House press secretary Robert Gibbs, said that scientists were in talks with BP "out of an abundance of caution to do no harm".