Northern Ireland’s police ombudsman is to examine claims that detectives did not properly investigate whether Sinn Fein president Gerry Adams covered up the crimes of his sex abuser brother.

Sinn Féin leader Gerry Adams' brother, Liam, was convicted last week of raping his daughter, Áine, over a six year period in the 1970s.

On Tuesday, Stormont's Health Minister Edwin Poots today called for a probe into how the Police Service of Northern Ireland (PSNI) handled the investigation.

In the past PSNI officers made a recommendation to the Public Prosecution Service (PPS) that no charges be brought against the Sinn Fein leader.

Poots told the Northern Ireland Assembly that the police ombudsman should examine the PSNI's role in the case, the BBC reports.

"Aine Adams was let down by the RUC (Royal Ulster Constabulary), she was let down by her uncle Gerry Adams and she has been let down to some extent by the PSNI," Poots said.

"I welcome the fact that there was a conviction in that case and the good work that was carried out by the PSNI and the Public Prosecution Service in bringing Liam Adams to justice but I do think that when it comes to the other issue of the cover-up of the crime, that the PSNI have questions to answer and they need to have those questions answered in a very public way.

"That's why I believe the ombudsman needs to look at the work of the PSNI to date.

"It is a very, very unusual set of circumstances and I think the PSNI should be asking for the ombudsman to look at their work, and, if they don't, I will.

"And I will be looking for independence to be applied in this case so that no one, and I mean no one in the public, has any sense that anybody is above the law."

A spokesman for Police Ombudsman Dr Michael Maguire has said an official complaint has been received. The ombudsman will now examine the matter before deciding if a formal investigation should be launched.

The Sinn Fein leader made his first report to police in 2007 about the allegations against his brother.

Responding to the backlash Gerry Adams said: "I know that I committed no offence and I know that I did what I considered to be the right thing and that I co-operated fully with the PSNI, with the PPS, with the courts, that I gave evidence in the courts," he said.

"So I don't have any concerns about that.

"I obviously am concerned that as members of my family pick up the newspapers this morning, and on the back of this press conference will pick up the newspapers tomorrow morning, and wonder why there is such an inordinate attention on this and on me.

"So that's my primary concern, my primary concern isn't about me."