McMonagle, from Limewood Street in Londonderry, was jailed last year for child sex offences.

The controversy prompted a review of his previous employment arrangements with Sinn Féin and the party's elected representatives.

It found for three months in 2020 he simultaneously held two full-time jobs working for two Sinn Féin politicians - First Minister Michelle O'Neill and West Tyrone MP Órfhlaith Begley - while also working as a party press officer.

The review said Sinn Féin "ought to have known" McMonagle was contracted to work for about 80 hours a week.

It found McMonagle was "likely to have misrepresented his employments and that neither Ms Begley nor Ms O'Neill were aware of this".

The matter was referred to the PSNI by the Stormont assembly's chief executive, Lesley Hogg.

In a letter to assembly members in January, she said she was required to report the issue "under the Assembly Commission's Fraud Prevention and Anti-Bribery Policy".

Following the PSNI concluding its enquiries, the assembly was approached for comment.

In January, the first minister said there were "lessons to be learned for everybody" as a result of the Stormont report into McMonagle's employment.

"I think it's been a very useful piece of work, because I think there's lessons to be learned for everybody in terms of how we employ people and actually how that's all fully accountable," she said.

The Sinn Féin deputy leader added: "We were at a time of Covid. It was a very short time in which he did work for me and there was an overlap. But I do believe there are lessons to be learned there of course."