More than €8m has been spent on the garda air units over the past six years.

In excess of €1m a year is spent maintaining the two garda helicopters.

The figures show a spend of €8,327,888 on maintaining the garda helicopters between 2011 and October last year.

The figures, released under the Freedom of Information Act, show a €1.2m spend in 10 months last year.

In 2011, a cost of €1,807,477 was associated with the helicopters. In 2012, this had dropped to €1,320,436.

While the 2013 figure was even less at €1,204,696 - while €1,478,206 was spent on them in 2014.

2015 saw €1,303,961 spent on the vehicles, and €1,216,114 was spent on them up to October 2016.

The helicopters may be used in a variety of operations - including policing of State events and monitoring gangland crime in 2016.

In 2015, they were also used to catch a criminal gang stealing ESB power lines.

The air units are based in Baldonnel on the outskirts of Dublin city and are deployed during incidents where there is a threat to life, or serious criminal and terrorist incidents.

Gardaí say they are also used for evidence gathering and photographic tasks.