Figures published by the General Register Office show 426 couples involving two foreigners with one partner from outside the EU were married in the Republic in 2016. It compares to 860 in 2015 and 1,163 in 2014.

The office figures reveal that 41% of such couples who notified the Irish authorities of their intention to marry last year did not proceed with their wedding.

Only about 20% of couples in that category failed to go ahead with a marriage ceremony between 2012 and 2014. There has been a significant reduction in the number of citizens from Pakistan involved in such marriages — down from around 400 in 2014 and 2015 to 58 last year.

The registrar general Kieran Feely said the problem of marriages of convenience, as a means of circumventing immigration controls, became more acute following a ruling by the European Court of Justice in the Matock case in 2008.

It allowed the non-EU spouse of an EU citizen to move and reside with their partner within the EU without having previously been lawfully resident in a member state.

The judgement did not apply to a non-EU spouse married to an Irish citizen.

Mr Feely said: “Non-EU nationals marrying Irish nationals are not entitled to EU Treaty rights in Ireland, so there is much less of an incentive to contract a marriage of convenience with an Irish citizen.”

The registrar general said the number of notices of intention to marry involving non-Irish EU and non-EU couples had grown “fairly dramatically” in recent years. They rose from 883 in 2012 to 1,584 in 2015 — an 80% increase.

In his annual report to the Department of Social Protection, Mr Keely said there had been an equally dramatic fall last year when the numbers fell by 56% to 702. “The introduction of the measures contained in section 18 of the Civil Registration (Amendment) Act 2014 has obviously had a significant impact,” said Mr Keely.

The legislation which came into effect in January 2016 allows for a marriage that is determined to be a marriage of convenience to be declared invalid.

It permits a registrar to consider certain matters where a notice of intention to marry is received from a foreigner. In suspicious cases, the registrar is obliged to make a report to a superintendent registrar who decides the matter as well as providing a copy of all records and information to the minister for justice.

The decision of the superintendent registrar can be appealed to the circuit court.

Mr Keely said the success of the legislation has also been assisted significantly by co-operation between the Department of Justice and the Garda National Immigration Bureau.