A document under the law in Ireland, is anything with writing on it - this may include paper, stone, a map, a plan, a graph, a drawing, a computer or a computer disc. Documentary evidence is admissible as evidence in court.
The Criminal Evidence Act 1992 deals with the rules that cover the admissibility of documentary evidence in criminal proceedings. In order that a court will accept documentary evidence in a criminal trial there are a number of safeguards in place to avoid abuse against the hearsay rule of evidence.
Section 8 of the Criminal Evidence Act 1992 gives the court discretion to exclude a document in the interests of justice, having regard to the circumstances. If a court is of the view that the document is unreliable, a fake or would result in unfairness to the accused, then the court has the option of excluding the document from the evidence.
The Act also allows either side (prosecution or defence) to challenge the credibility of the documentary evidence and to give evidence to the court in this regard.
If the Gardai or prosecution wish to have any documentary evidence included in a court case a copy of the document must be served on the accused at least 21 days before the court case.
Before the Criminal Evidence Act 1992, there was a best evidence rule, which stated that it was necessary to produce the original of a document for it to be introduced as evidence in a criminal case. It is, however, now possible to introduce a copy of a document as evidence.
In civil cases the best evidence rule still applies. However, there are exceptions to the rule. The court will accept a copy of the document, or oral evidence about the existence and content of the document, if the original has been destroyed or lost, or is impossible to obtain.
For more detailed information you should seek legal advice.