Tougher action against sham marriages and illegal workers is reaping rewards, with an increase in the number of people being arrested for immigration offences and deported from Northern Ireland, ministers have said.
A spate of arrests in relation to sham marriages has been reported by the UK Border Agency.
The number of "enforcement operations" recorded in Northern Ireland soared by a third last year, while there was a 50% rise in the number of arrests.
The jump was mirrored by a 23% increase in operations across the United Kingdom and fines that leapt from £4.2m to £7m - a rise of two-thirds.
It was also revealed that 22 illegal immigrants had passed through the controversial detention centre in Larne in its first fortnight.
The centre, which came into use on July 11, had been opposed by local residents and human rights activists. There is currently one person being held at the centre, which has the capacity to hold 21 prisoners for up to seven days, officials confirmed.
Immigration Minister Damian Green said: "We have turned up the level of activity and what's particularly important is that it is increasing the public's confidence.
"People ask what we are doing, perhaps about a factory that everybody knows is dodgy.
"They are very pleased to see that we are making thousands of enforcement visits."
Mr Green also told the Belfast Telegraph that his department was working closely with gardai to clamp down on people-smuggling across the border.
This includes sharing intelligence, data and and working to align the two countries' visa regimes, he said.
He also said the Government was getting to grips with the 500,000 "legacy cases" of long-forgotten immigration cases inherited from Labour.
The figures show that the UK Border Agency Northern Ireland and Scotland, which has enforcement teams based in Belfast, Glasgow and Edinburgh, carried out 1,068 enforcement visits in the year ending in April, up from 801 in 2009/10.
There was only a slight increase in civil penalties issued, from 167 to 170, but the Government's estimate of the proceeds from penalties recovered jumped from £200,000 to £500,000.
The Agency's operations included visits to firms suspected of employing illegal workers, to foreign nationals who have overstayed on their visas or entered the country illegally, or in connection with sham marriages.