Economic recovery in Northern Ireland would "grind to a halt" without migrant workers, a business leader has said.
Nigel Smyth, Northern Ireland director of the CBI, spoke after a report showed migrant workers had contributed around £1.2bn to the economy between 2004 and 2008.
Migrant workers were helping sustain economic growth and filling labour shortages by bringing in much-needed skills, research by the Centre for Democracy and Peace Building found.
Workers from overseas - accounting for 4% of the workforce - were also enriching society through cultural diversity.
According to separate research commissioned by the Northern Ireland Assembly, almost 122,000 long-term international migrants arrived in Northern Ireland between 2000 and 2010.
Many arrived following EU expansion in 2004, when EU membership expanded to include countries like Poland, Lithuania, Slovakia and Slovenia.
Nigel Smyth, director of the CBI in Northern Ireland, said immigration has been instrumental in helping many sectors of the economy, including food processing, IT, and hospitality.
Mr Smyth said: "Undoubtedly, immigration has helped keep the wheels of this recovery turning by plugging skills shortages, in particular in food processing, IT and the hospitality sector.
"This has led to more jobs and driven growth. Without free movement of workers, the recovery would grind to a halt."
The CDPB found migrants contribute more to the economy in tax than they use in public services.
In the UK, 81.5% of migrants are employed, while less than 5% of EU migrants claim Jobseekers Allowance.
The cost to the NHS of temporary migrants using the service is around 0.01% of its £109bm budget.
Mr Smyth added: "We are concerned however about where the debate on immigration is heading nationally as we build up to the next General Election - there is a mismatch between the rhetoric and the reality."
The report sought to address myths which plague the immigration debate, and focused on areas such as population, employment, housing, benefits, economy, healthcare, education, crime, and social cohesion.
Lord Alderdice, the chairman of the Centre for Democracy and Peace Building, said: "The report highlights contributions in tax, skills, labour and cultural diversity (of migrants) - enriching our society rather than threatening it."
Professor Peter Shirlow, one of the writers of the report, added: "People need to be educated about the facts. We frequently hear claims that migrants take our jobs and use up our limited services. Migrants pose no threat to our society."
The CDPB - whose founding directors include former Alliance Party leader Lord Alderdice and DUP MP Jeffery Donaldson - was set up to share Northern Ireland's experience of "peacebuilding and conflict resolution" around the world. Research by the CBI found 63% of its UK members feel the free movement of labour has been beneficial.
Immigration is currently the most contentious issue in UK politics. To try and limit immigration, Prime Minister David Cameron is looking to change how the principle of freedom of movement works within the European Union. It emerged this week the German Chancellor Angela Merkel warned the PM that his attempts to restrict migration will risk the UK leaving the EU.