A U.K. newspaper published more leaked memos from Britain's ambassador in Washington on Sunday, despite a police warning that doing so might be a crime.

In one 2018 cable published by the Mail on Sunday, U.K. ambassador Kim Darroch says U.S. President Donald Trump pulled out of an international nuclear deal with Iran as an act of "diplomatic vandalism" to spite his predecessor, Barack Obama.

The memo was written after then-Foreign Secretary Boris Johnson visited Washington in a failed attempt to persuade the U.S. not to abandon the Iran nuclear agreement.

"The outcome illustrated the paradox of this White House: you got exceptional access, seeing everyone short of the president; but on the substance, the administration is set upon an act of diplomatic vandalism, seemingly for ideological and personality reasons — it was Obama's deal," Darroch wrote.

Darroch announced his resignation last week after the newspaper published cables in which he'd branded the Trump administration dysfunctional and inept. The White House responded by refusing to deal with him, and Trump branded the ambassador a "pompous fool" in a Twitter fusillade.

U.K. police are hunting the culprits behind the leak — and, contentiously, have warned journalists that publishing the documents "could also constitute a criminal offence."

Tory leadership hopefuls defend reporting

Yet both Johnson and Jeremy Hunt, the two contenders to become Britain's next prime minister, have defended the media's right to publish.

"We have to make sure that we defend the right of journalists to publish leaks when they are in the national interest," Hunt said.

British officials have said they have no evidence that hacking was involved in the documents' release, and that the culprit is likely to be found among politicians or civil servants in London.

Police are investigating the leak as a potential breach of the Official Secrets Act, which bars public servants from making "damaging" disclosures of classified material. Breaking the act carries a maximum sentence of two years in prison, though prosecutions are rare.