The British government covered up a failed test of a nuclear-capable missile last year, weeks before a vote in Parliament on the extension of the country's Trident submarine-based system, The Sunday Times reported.
The missile suffered a "serious malfunction" during a test off the coast of Florida in late June, but the government decided to cover up the failure to prevent possible damage to the public credibility of Trident, the newspaper quoted an unnamed senior naval source as saying.
The Sunday Times said the missile went off course and may have veered toward the United States.
"There was a major panic at the highest level of government and the military after the first test of our nuclear deterrent in four years ended in disastrous failure," the source was quoted as saying.
"If the information was made public, they knew how damaging it would be to the credibility of our nuclear deterrent."
The missile was not armed with a nuclear payload for the test, reported the paper.
The source said an upcoming parliamentary vote on Trident on July 18 had made the failure "all the more sensitive."
Officials say British Prime Minister Theresa May was told about the June test of Britain's nuclear deterrent system when she took office last year.
Downing Street did not confirm or deny the report that one of the unarmed missiles fired during the test had malfunctioned.
Opposition leaders have raised concerns about a possible cover-up because Parliament was not told about the test before it debated whether to renew the aging Trident missile system.
May's spokeswoman told reporters Monday that she had been briefed about the test. She said the government does not discuss operational details of tests.
Prime Minister Theresa May, who succeeded David Cameron on July 13, told Parliament that Britain needed to spend some 40 billion pounds (49 billion dollars) on a new Trident system to deter "serious threats," warning of "a continuing risk of further proliferation of nuclear weapons."
May did not mention the failed missile test during the debate in parliament.
Asked if she knew about the failed test during an interview on the BBC's Andrew Marr show on Sunday, May declined to answer, but said she has "absolute faith" in Trident missiles.
"When I made that speech [on July 18]... what we were talking about was whether or not we should renew our Trident, whether or not we should have Trident missiles and an independent nuclear deterrent in the future," May said.
Pressed again on whether she knew about the failed test, she replied: "There are tests that take place all the time, regularly, for our nuclear deterrent."
According to The Times, Britain has only conducted five tests of Trident missiles from submarines since 2000, partly because each test costs around 17 million pounds.
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