The Police Service of Northern Ireland has rejected demands by a Conservative MP to investigate a former Downing Street official's decision to warn a leading Sinn Féin figure that she would be arrested if she returned to the North.

This week, former British prime minister Tony Blair told a House of Commons inquiry the peace process would have faced "huge problems" if Rita O'Hare, who remains wanted in Britain for the attempted murder of a British soldier, had been arrested in 2000.

Plymouth Conservative MP Oliver Colvile has complained that Jonathan Powell broke the law by warning Ms O'Hare that she remained at risk of arrest if she returned to Northern Ireland or travelled to Britain.

In July 2000, Mr Powell, Mr Blair's top adviser, told the then British attorney-general Lord Williams he had met in Dublin, Irish and British officials, with Sinn Féin's president Gerry Adams and Ms O'Hare.

Ms O’Hare was charged in Belfast in 1972 with the attempted murder of a British soldier in Belfast the year before, along with malicious wounding and firearms charges. Released on bail, she fled to the Republic.

In his memoirs, Mr Powell wrote: “My recollection is that at the end of that meeting Gerry Adams suggested jocularly that Rita O’Hare should join us at the next meeting in Belfast. I said it would not be a good idea, as it was likely that she would be arrested.”

In a letter to Mr Colvile, PSNI Supt Sam Donaldson said the PSNI had reviewed his complaint to see "if there are grounds to suspect the commission of any offence by any identifiable person".

Saying it had considered where the remarks had been made, Supt Donaldson said: “It is my belief that in the circumstances there are no reasonable grounds to suspect that any criminal offence has been committed.”

In his evidence to the Commons Northern Ireland Affairs Committee last September, which is investigating the decision to tell more than 200 republicans that they were not wanted for prosecution, Mr Powell said the British government had been trying in 2000 "to find a solution to her case".

"Gerry Adams and Martin McGuinness made the case that she should come back, because she could contribute to the peace process very strongly if she came back, and her father was about to die, as indeed he did. We were looking to see if we could find a solution to that.

“We could not have found a solution to it had she come back and been arrested, feeling she had fallen into a trap by me trapping her into coming back; the peace process would have been dead. It would have been a very bad idea,” he told MPs.

Mr Powell has rejected Mr Colvile’s suggestions he acted improperly, pointing out that Ms O’Hare had never returned to Northern Ireland since she had left and did not need a new warning from him to stay away.

During his appearance before MPs, the North’s attorney general John Larkin said urging a fugitive not to come back, lest they be arrested, would raise questions that the person giving the warning had sought to pervert the course of justice.

However, he said laws may not have been broken if the fugitive had “made it absolutely clear that they are not coming back and you happen to pass on to that person that it is not safe for them to come back”.

On the PSNI's response, Mr Colvile told The Irish Times, "I will be writing to the Garda to ask them to investigate."