The number of undocumented Irish is growing in Australia as many overstay visas because they cannot afford to move back home.

The number of Irish on temporary visas in Australia has decreased by nearly 50 percent in the past two years because of tighter immigration laws and fewer job opportunities.

“We are talking about the creation of a whole new undocumented section of Irish society in Australia now, and that is something we should be concerned about,” says Dr Mary Gilmartin, who lectures about Irish migration at the department of geography at Maynooth University.

Because of tighter immigration laws, and new caps on the number of skilled migration permits issued, Gilmartin says that it is now “increasingly difficult to translate temporary visas into permanent residency” in Australia.

A total of 401 Irish citizens were “returned or removed” from the country for violating the conditions of their visa in the 12 months to June 2015, an increase of 37 percent in the past two years.

Dr Gilmartin said: “By definition, it is very difficult to get a sense of an undocumented community, but that increase, as well as the anecdotal evidence from people in Australia, would suggest that many people are overstaying and spending many years undocumented without any sense of amnesty.”

The Irish Times reports that figures released by the Australian Department of Immigration show that between July 2014 and June 2015, 92 Irish citizens were “removed” after being arrested and held at immigration detention centers.

Another 309 returned to Ireland voluntarily after overstaying their visas.

Liz O’Hagan of the Claddagh Association, a welfare group working with Irish citizens in Perth, said people are choosing to overstay because there is “a reluctance to return to Ireland for financial reasons.

“People cannot afford the resettlement costs,” she said.

Róisín Trainor of the Irish Australian Welfare Bureau in Sydney said the organization had assisted with many cases where Irish people were detained for overstaying, and said “it has been highly stressful for those involved.”

The number of Irish temporary visa holders has also dropped. In June 2015, a total of 23,205 Irish citizens were in Australia on temporary visas, a decrease in the number the same month in 2013.

In 2011/12, when the number peak, 19,492 Irish citizens were granted their first year working holiday visa, compared to just 5,221 in the 12 months to June 2015.

The figures also show a significant rise in the number of temporary visas held by Irish citizens that were canceled before they expired.  O’Hagan said this rise reflected the large numbers of Irish construction workers on employer-sponsored visas being made redundant as the sector experienced further decline.

According to The Irish Times, 3,561 temporary visas, including working holiday visas and employer-sponsored work permits (called 457 visas), held by Irish people were canceled in the 12 months to June 2015, up from 2,850 the previous year and just 985 in 2010/11.