UK police have found that a leak from a meeting of the National Security Council (NSC) does not amount to a criminal offence.
In a press release, Metropolitan Police assistant Commissioner Neil Basu, head of the Met's Specialist Operations, said that after examining the nature of the material disclosed to the media he concluded that none "contained information that would breach the Official Secrets Act".
On Wednesday, British prime minister Theresa May abruptly sacked defence secretary Gavin Williamson for divulging state secrets followed a newspaper report on a plan to give China's Huawei limited access to Britain's next-generation communications network. Williamson has strenuously denied any wrongdoing.
But the British police officer said there would be no probe into the leak.
"The leak did not cause damage to the public interest at a level at which it would be necessary to engage misconduct in a public office. It would be inappropriate to carry out a police investigation in these circumstances."
Williamson's dismissal comes as Theresa May's authority is under scrutiny over the government's failure to deliver Brexit, and was announced on the eve of local elections in which the ruling Conservative Party is expected to fare badly.
Penny Mordaunt, the international development secretary, has been made Secretary of State for Defence, the first time a woman has held the post.
In a meeting with Williamson on Wednesday evening, the prime minister said the inquiry had found "compelling evidence" that he was responsible for the leak.
The published text of May's letter to the sacked minister describes the "unprecedented leak" from the NSC meeting as "an extremely serious matter".
"The prime minister has this evening asked Gavin Williamson to leave the government, having lost confidence in his ability to serve in the role of defence secretary and as a member of her cabinet," said 10 Downing Street in a statement.
"The prime minister’s decision has been informed by his conduct surrounding an investigation into the circumstances of the unauthorised disclosure of information from a meeting of the National Security Council.
"The prime minister thanks all members of the National Security Council for their full cooperation and candour during the investigation and considers the matter closed."
Williamson has insisted vehemently that he is not the source of the leak, posting on Twitter his letter to the prime minister.
Various UK media outlets have reported his forceful denials: "I swear on my children's lives that I'm innocent"... "(I've been) completely screwed"... "hung for a crime I didn't do". The ex-minister described the inquiry as "a witch hunt from the start... in a kangaroo court with a summary execution," Sky News reported.
Huawei and national security
The probe came after the Daily Telegraph reported that the UK was going to grant Chinese technology giant Huawei a restricted role in building parts of its 5G network.
That information is said to have come from a leak of the UK's National Security Council. It is made up of senior cabinet ministers and has at its helm the prime minister under whom weekly meetings are conducted. Meetings often involve sharing of secret intelligence and ministers are bound by the Official Secrets Act.
Huawei, the world's biggest producer of telecoms equipment, is under intense scrutiny after the United States told allies not to use the provider for fear it could be a vehicle for Chinese spying.
The company categorically denied this.
Allied nations are now walking a tightrope, with the US pressuring them to take a firm stance in the face of Huawei but also not wanting to bite the hand of China and risk trade and diplomatic sanctions.