A report published by the Central Statistics Office details a massive rise in the employment of illegal immigrants by private security companies, with figures more than tripling in the last three years.
2012 figures show that security firms in the Republic of Ireland provided work for as many as two foreign nationals who resided in the state illegally. By 2015 - the last year for which figures are available - that number had leapt to seven. The data collected suggests that both EU and non-EU nationals are working in the sector.
Unconfirmed data suggests that as many as an eighth man could be working as a security guard in the North.