Claims that Catholics in Northern Ireland were murdered by a top-secret loyalist "inner circle" have led to the largest number of libel writs ever issued in relation to a single book.
More than 50 writs have been issued in the High Court in Belfast against the publishers of Sean McPhilemy's The Committee: Political Assassination in Northern Ireland.
Among those claiming damages are Mr Trevor Forbes, a former head of the RUC Special Branch, and Sunday Times journalists Liam Clarke and Barry Penrose.
Brothers Mr David and Mr Albert Prentice, from Portadown, Co Armagh, have already successfully sued in the US and are understood to have been awarded $1 million.
Mr McPhilemy's book, based on his Channel 4 programme The Committee, alleged RUC officers, unionist politicians, businessmen and loyalist killers were involved in a conspiracy to murder Catholics.
The writs, which include claims for aggravated and exemplary damages, have been issued by the Belfast law firm Johnsons.
Senior litigation partner Mr Paul Tweed said: "Our clients have been subjected to totally false allegations of a serious defamatory nature."
The book is not for sale over the counter in Britain or Ireland but can be bought on the Internet.
Mr Tweed said: "The writs had been issued against USA and UK-based Internet distributors who have been publishing and distributing the book. They include Amazon.com, Amazon.co.uk, BarnesandNobel.com, and W H Smith, trading as the Internet Bookshop.
"We have instructions to aggressively prosecute these actions with a view to vindicating our clients' reputations at the earliest opportunity."
Mr McPhilemy's book, which was published in the US in 1998, named 24 of the alleged conspirators, including Billy Wright, leader of the Loyalist Volunteer Force, who was murdered in the Maze Prison by three INLA prisoners.
Channel 4's broadcast of The Committee in 1991 caused uproar. The RUC launched an investigation but the company and Box Productions, which made the documentary, refused to identify their key witness. They were prosecuted for contempt and jointly fined £75,000.
Top libel QCs Mr Michael Lavery and Mr David Ringland have been engaged to represent the claimants. They have drafted statements of claim alleging the book meant their clients were terrorists who were engaged in sectarian murder.
The lawyers claimed the reputations of their clients had been greatly injured and they had been brought into public scandal and contempt.
Mr Tweed said he hoped all the actions would be heard before the end of the year.