The programme was established by the State in the wake of the murder of journalist, Veronica Guerin 20 years ago in 1996.
A state witness against four members of the John Gilligan drugs gang, Charlie Bowden, was the first to be admitted to the programme on his release from prison.
More recently, Steve Collins, the father of gangland murder victim, Roy Collins, moved abroad with the help of the State after it purchased properties owned by Mr Collins in Limerick to allow his family start their new life.
Roy Collins was shot dead by a member of the notorious McCarthy-Dundon gang in 2009 and in March 2012, Mr Collins and his family required the State’s help to start a new life abroad after their life in Limerick became intolerable due to constant threats.
Figures provided by Minister for Justice Frances Fitzgerald in a written Dáil response to Indepoendent TD Tommy Brougham show that €1.19m was budgeted for the witness protection programme last year.
This compared to a combined spend of €1.15m for 2013 and 2012 while the spend in 2014 was €1.2m.
The budget for the programme this year is another €1.19m.
The projected spend this year compares to a spend of €700,000 in 2011 and €700,000 in 2010.
In her written Dáil reply, Ms Fitzgerald said: “The Garda Síochána has operated a Witness Security Programme since 1997 to respond to attempts by criminal and other groups to prevent the normal functioning of the criminal justice system, including threats of violence and systematic intimidation of witnesses.”
She said: “The Witness Security Programme is operated by the garda authorities, overseen by the Crime and Security Section at Garda headquarters supported by the Special Detective Unit and other garda resources as necessary.”
She added: “The operation of the programme and the resources required for it are kept under continuous review by the Garda authorities.
“By virtue of the highly confidential nature of the Witness Security Programme and the need to maintain the protection of persons who receive support from it, it has not been the practice of successive ministers to detail the specifics of its operation.”
It is an offence to identify the whereabouts or any new identity of a witness who has been relocated under the programme.