The PSNI re-investigated the online threats, which purported to be from neo-Nazi terror group Combat 18, after the Police Ombudsman upheld a complaint from Ms Devlin in 2021.

The Police Ombudsman had criticised the PSNI for having “failed to take appropriate measures to secure the arrest of the suspect, who lived in another part of the UK” following the journalist’s initial report to police in 2019.

The message, which included a threat of rape against Ms Devlin’s then newborn son, was sent to her personal Facebook account and included personal information about her family and what the sender believed to be where she lived.

Following its re-investigation, the PSNI sent a file to the PPS in January 2022, but it was considered to fall short of the evidential test, the BBC reports.

A spokesperson for the PPS said: “After careful consideration, and taking into account all the facts of the case, and the advice of independent counsel, it has been determined that for this reason the evidence was insufficient to provide a reasonable prospect of conviction of this individual for any offence.”

The decision not to prosecute has been criticised by Amnesty International, which supported Ms Devlin in lodging the Police Ombudsman complaint and said she had been “let down repeatedly, first by an inadequate police investigation and now by a failure to prosecute”.

Patrick Corrigan, Amnesty’s Northern Ireland programme director, said: “If the case is considered a litmus test over whether Northern Ireland’s criminal justice system will protect journalists from intimidation, then we must conclude that it is failing.

“This PPS decision will strengthen a feeling of impunity among those who already feel emboldened to make threats of violence against journalists.

“Threats designed to shut down press scrutiny of criminal and paramilitary activity cannot be allowed to succeed in undermining press freedom in Northern Ireland.”