AN author has vowed to press ahead with his book about child killer Shaun Armstrong as legal action against him looks certain to be dropped.

Paedophile Armstrong, the killer of Hartlepool toddler Rosie Palmer, was suing writer Bernard O'Mahoney for breach of confidentiality and the profits of any book which may be written.

But according to Mr O'Mahoney, Armstrong, who has used thousands of pounds of public money to pursue his legal bid, has decided to drop the case after consulting an independent barrister.

The legal bid was due to go ahead at the Royal Courts of Justice in London on July 8, but the court is now likely to hear an application for the case to be withdrawn.

Mr O'Mahoney, of Lincolnshire, extracted a confession from Armstrong by writing to him, pretending to be a woman and striking up a relationship. The author later handed over his letters to Cleveland Police but Armstrong claimed his confidence had been breached.

Yesterday, Mr O'Mahoney said: "I feel a little bit cheated really because I knew he was lying and was quite relishing the thought of exposing him in public.

"He's a vile fantasist, his case has just been ludicrous and it has cost the tax payer thousands of pounds."

Three-year-old Rosie was abducted and murdered by Armstrong after she had left her home in Henrietta Street, Hartlepool to buy an ice lolly.

Mr O'Mahoney has now vowed to write his book on Armstrong and other notorious paedophiles. They include Richard Blenkey, who molested and strangled seven-year-old Paul Pearson in Cleveland in 1991, Roy Whiting, who abducted and murdered eight-year-old Sarah Payne in West Sussex and Howard Hughes, who raped and killed Cheshire schoolgirl Sophie Hook after snatching her from a tent in her uncle's garden.

Mr O'Mahoney, who has also vowed to send any information he has on Armstrong to his parole board, has corresponded with all the men, pretending to be someone else.

"There will be no gratuitous details. It will be more about the people who commit these type of crimes and their mindset," he said.

Councillor Kevin Kelly, a former member of the Rosie Palmer Foundation, said: "I am relieved the case is going to be dropped. The family deserve to be left in peace now."

Elkan Abrahamson, Armstrong's solicitor, was unavailable for comment yesterday.