Net migration is calculated as the difference between the total number of people entering the country and leaving it.
"Net long-term migration to the UK was estimated to be 260,000 in the year ending June 2014, a statistically significant increase from 182,000 in the previous 12 months," the report published on the institute's website stated.
According to the paper, there was a significant increase of 45,000 EU immigrants in the United Kingdom, while the influx of non-EU citizens also rose by 30,000 in the year ending June.
One of the main reasons for moving to Britain cited in the report was employment. The number of EU migrants employed in the United Kingdom increased by 16 percent in the July to September period in 2014 compared to the same quarter in 2013.
The report follows Prime Minister David Cameron claims that he intends to curb the number of EU migrants entering the country by tens of thousands.
According to British media reports, Cameron will deliver a major speech on immigration in the coming days.
