The test firing of a Trident missile from a Royal Navy submarine has failed, for the second time in a row, Ednews reports referring to the BBC.
The latest test was from HMS Vanguard off the east coast of the US and was witnessed by the defence secretary.
The missile's booster rockets failed and it landed in the sea close to the launch site, according to the Sun, which first reported the malfunction.
When on patrol the missiles would usually be armed with a nuclear warhead but they are not fitted for test fires.
This is highly embarrassing for both the UK and the US manufacturer of the Trident missile.
British tests of Trident missiles are rare, not least because of the costs. The price tag of each missile is around £17m and the last test was in 2016 when it also ended in failure when the missile veered off course.
Both the Defence Secretary Grant Shapps and the head of the Navy were on board HMS Vanguard, which has just had a more than seven year refit, when it fired the unarmed test missile in January.A defence source close to the Mr Shapps insisted the Trident "could absolutely fire in a real world situation" if it needed to.
"The issue that occurred during the test was specific to the event and would not have occurred during a live armed fire," the source said.