“Misconduct in public office is a serious common law offence which requires prosecutors to show that a public officer deliberately breached their duty in a way that represents a serious abuse of public trust,” he explained.

“It is not enough for there to have been an error of judgment – the conduct must be wilful and sufficiently serious.”

Judge added: “If sensitive government material was shared without proper authority, the question would be whether that amounted to a deliberate breach of official duty. Prosecutors would need to establish intent, seriousness and whether the conduct crossed the threshold into criminal wrongdoing.

“An arrest under suspicion does not mean a charge has been brought, and it does not imply guilt.”

He concluded: “Police must gather and assess evidence before deciding whether the case meets the charging threshold.”

More updates are expected.