Sir Kim Darroch latest: Met launch probe into leak of official communications which led to ambassador's resignation
Sir Kim quit his post amid the diplomatic furore, after memos he wrote which criticised the Trump administration were published.
An investigation was launched by the Foreign Office and now Scotland Yard has confirmed its own inquiry.
The Met’s Assistant Commissioner Neil Basu said: “Following a cross-government investigation led by the Cabinet Office a Gateway Process has occurred today with the Metropolitan Police into the alleged leaking of official communications involving Sir Kim Darroch.
“As a result the Metropolitan Police Counter Terrorism Command, who take national responsibility for investigating allegations of criminal breaches of the Official Secrets Act, has launched a criminal investigation.
“Given the widely reported consequences of that leak I am satisfied that there has been damage caused to UK international relations, and there would be clear public interest in bringing the person or people responsible to justice.”
Sir Kim announced on Wednesday he was resigning, stating his position had become “impossible” following the leak of the cables in which he described President Trump’s White House as “inept” and “dysfunctional”.
His comments drew a furious response from the president who denounced him as a “very stupid guy” and a “pompous fool” and said the the White House would no longer deal with him.
Mr Basu added: “The investigation will be reviewed at every stage to ensure a proportionate investigation is undertaken.
“I would say to the person or people who did this, the impact of what you have done is obvious. However, you are now also responsible for diverting busy detectives from undertaking their core mission. You can stop this now. Turn yourself in at the earliest opportunity, explain yourself and face the consequences.
“Also, to anyone who knows or suspects those responsible, or who has any information, please come forward.
“Exercise your public and civic duty and call the police on 0800 789321 without delay. That call will be treated in strictest confidence.
“The publication of leaked communications, knowing the damage they have caused or are likely to cause may also be a criminal matter.
“I would advise all owners, editors and publishers of social and mainstream media not to publish leaked Government documents that may already be in their possession, or which may be offered to them, and to turn them over to the police or give them back to their rightful owner, Her Majesty’s Government.”