The brother of murdered Journalist Veronica Guerin says he turned down requests to take part in a documentary about John Gilligan.
Jimmy Guerin says the programme, and a book about Mr. Gilligan, are an "insult" to the Irish Judicial System.
Gang boss Gilligan will tell "his side" of the story in a three-part documentary due to air on Virgin Media Television.
Mr. Gilligan was acquitted of the murder of Investigative Journalist Veronica Guerin in 2002.
Jimmy Guerin said it is "more than disappointing" that a national television broadcaster, producers, publishers and journalists have chosen to air the documentary and to publish the book.