New Zealand's net population gain from migration hit a new all time monthly high of 6748 people in January, surpassing the previously monthly record of 6692 in February 2003.

Statistics NZ said there was an annual net gain (the number of permanent and long-term arrivals less the number of permanent and long-term departures) of 53,800 people in the 12 months to the end of January, which was more than double the 25,666 net migration gain that occurred in the 12 months to January 2014.

The total number of immigrants arriving in this country on a permanent and long term basis was 111,522 in the year to January, while 57,725 people left the county on a permanent or long term basis in the same period, leaving a net population gain of 53,797.

January was also the sixth straight month in row in which the annual record for net migration gain was broken.

The biggest net gain of migrants in the year to January came from the India (10,776), followed by China (7588 plus 615 from Hong Kong), the UK (5,072), the Philippines (3,753), France (2726) and Germany (2608).

There was a net migration loss of 2888 people to Australia in the year to January, although the loss of people to Australia is slowing on both a monthly and annual basis.

In the year to January 2014, 17,064 people departed permanently for Australia and in the year to January 2013, 37,936 people headed across the ditch from this country.

In January this year, only 433 people headed to Australia permanently, compared with 1342 in January 2014 and 3883 in January 2013

Statistics NZ classifies permanent and long term travellers as anyone arriving or departing for 12 months or more.

Over the last few years the number of people arriving in this country has been increasing substantially while the number leaving has been in substantial decline, resulting in rapid population growth form migration.

According to Statistics NZ, in the year to January 2012 there was a net migration loss of 3134 people, which turned around to a net gain of 12 people in the year to January 2013, which climbed to a net gain of 24,666 in the year to January 2014 and exploded to a net gain 53,797 in the current year.

However the population growth from migration could go higher still, with Westpac saying it is yet to peak.

In it its latest First Impressions report commenting on the latest migration figures, Westpac's senior economist Felix Delbruck said the bank's economists expected net migration to peak at around 60,000 a year.

"That means continued very strong population growth, with the associated boost to retail spending and housing demand," he said.