In an action for defamation truth of the defamatory statement is a complete defence. But under the criminal law truth of the statement is no defence. If the defendant proves that the defamatory statement is true, no action will lie for it, even if he had published the statement maliciously.
If the statement is true the purpose or motive with which it was published is irrelevant. It is not necessary for the defendant to prove that every words of the defamatory statement is true. It will be sufficient, if the statement. Though not perfectly true is substantially correct. It is not necessary to prove that the statement is literally true, it is sufficient if it is true in substance. Minor details need not be proved as true because it makes no different effect on the mind of the reader then the actual truth would do.
In Alexander v. N.E. Rly., the defence had published a notice stating that the plaintiff had been convicted of travelling in a train without a ticket, and had been fined one pound with three weeks imprisonment in default of payment. In fact, the punishment given to the plaintiff was only for two weeks in default of payment. The Court held that the defence of truth was correct, because the statement was substantially true, and the main imputation was correct, minor difference would not affect the truth of the statement accordingly the defendants were not liable because the statement was substantially accurate.
If the statement is in the form of an innuendo, the defendant had to prove the truth of the statement arising out of the meaning of the words used in the innuendo. For example, it would not be proper to call a man, a convicted editor, if he had already undergone his punishment and the punishment has come to end. But if a person knows that particular man has been convicted by a competent court, he can call him a convict, and no action for defamation can be brought against him. If a defamatory rumour or hearsay report or its repetition is made. The defendant has to prove the truth of his statement. Where a number of allegations are made the defendant is free to prove the truth of some of the statements. If he can prove that the alleged complaints made by him, can be separated from the rest, he can be absolved from liability. But if they are also closely connected with each other that become only on allegation, it can be a full allegation. If there no such rule, then every person can take the help of rumour and easily escape from the liability for libel.
If the defendant fails to prove the truth of the statement, the defence of justification cannot be availed.