An independent investigation into how a sex offender from Ireland was free to rape and murder a mother-of-three has recommended a change in the law be considered to compel offenders to disclose their convictions when entering the country.

Patrick Rea, 42, strangled Mary McLaren and dumped the 34-year-old's body in undergrowth after meeting her at a Dundee nightclub in 2010.

He was jailed for a minimum of 20 years following a trial at the High Court in Edinburgh last year. He was also placed on the sex offenders' register indefinitely.

After his trial, it emerged that Rea was a known sex offender in Ireland, where he held previous convictions for rape, sexual assault, assault and false imprisonment.

The Association of Chief Police Officers in Scotland (Acpos) ordered a review into the level of scrutiny of Rea before the killing.

In its findings published today, the Operation Xylose significant case review recommended that police forces in Scotland should be instructed to obtain previous convictions for all foreign nationals investigated or reported in their area, and ensure they are submitted to the Crown Office and Procurator Fiscal Service (COPFS).

It recommended that legislation be considered to compel "foreign nationals with convictions for sexual and other specified crimes, and UK nationals convicted of such crimes while abroad, to disclose their convictions upon entering or returning to, the United Kingdom".

At this time there is no requirement in law for a foreign national to disclose their previous convictions on arrival in the UK, the report said.

This is further to those people who arrive in the country illegally and those who have avoided court proceedings in their home country.

The report also recommended that An Garda Siochana, Ireland's national police force, consider "learning points" arising from the review, with a view to developing the inter-country management of sex offenders who travel between Ireland, Scotland and the rest of the UK.

Rea travelled between Ireland and Scotland regularly and often used different names, which the review said caused police "practical difficulties".

The report states that Rea was known to officers in Scotland.

On New Year's Eve 2009/10, he gave false details to Grampian Police when they stopped his vehicle.

In the following days, concerns were raised about his background and officers liaised with Interpol and An Garda Siochana, which confirmed he was a registered sex offender.

Grampian applied for a notification order and received an interim order on February 18 2010, about a week before Mrs McLaren went missing.

He was questioned by police in Glasgow on March 1 but was released before the Grampian interim notification order could be served on him.

Tayside Police caught up with him soon after and he was later charged with Ms McLaren's murder.

The report has recommended that the Scottish Police Services Authority and Acpos consider reviewing existing mechanism to identify and merge records, to ensure all intelligence entries are available in a single record.

Tayside Police Assistant Chief Constable Angela Wilson said "nothing would have altered his (Rea's) evasiveness or murderous intent".

She said: "The responsibility for Mary's brutal murder lies squarely with Patrick Rea.

"Known by several different names, he led an itinerant and frequently criminal lifestyle through which he sought to evade the authorities and treat the law and innocent members of the public with contempt.

"His wickedness left Mary's family to agonise over her disappearance and then he continued to deny his crimes when her body was discovered, subjecting her family to a long and harrowing trial.

"The police are responsible for preventing serious and violent crime where and wherever possible, as well as the detection of offenders.

"Reviews such as this allow us to scrutinise where we can improve and strengthen procedures and practice.

"It is Rea and Rea alone who is responsible for his actions. Nothing would have altered his evasiveness or murderous intent.

"If it were not for him, Mary McLaren would be alive today."

The report, which made a total of 15 recommendations, was commissioned by Lothian and Borders Assistant Chief Constable Iain Livingstone, who was the lead officer for the Acpos public protection portfolio.

Ms Wilson added: "Lessons are there to be learned and Acpos and all of our partners are ensuring that all the recommendations are carefully considered, acted upon and the learning shared.

"Rea has shown himself to be a devious deviant itinerant who committed his crimes upon vulnerable women. At the time he murdered Mary McLaren he was not subject to any requirements of the Sexual Offences Act 2003.

"But learning points have emerged for us all as a result of this tragic murder. We must all ensure that information is recorded correctly and accurately, as well as being used and shared properly.

In a statement, Ms McLaren's family said today: "Mary is still in our hearts and not a day goes by when we don't think of her.

"Patrick Rea took Mary away from us and nothing can be done to bring her back to us.

"We cannot forget Patrick Rea or forgive him for what he has done.

"But we do hope that we can put this evil man to the back of our minds and move forward as a family with the many happy memories that we have of Mary."