An ex-nurse accused of inventing a murderous Westminster VIP paedophile ring has been found guilty of 12 counts of perverting the course of justice and one of fraud.

Carl Beech, 51, once only known in media reports as "Nick", alleged senior politicians, Army top brass and security chiefs were involved in sadistic sexual abuse and that he witnessed them murder three boys in the 1970s and 1980s.

The Metropolitan Police investigated his claims, raided homes and interviewed alleged suspects, but the £2 million Operation Midland ended without making a single arrest, jurors at Newcastle Crown Court have heard.

Met Police raided the homes of 91-year-old Normandy veteran Field Marshall Lord Bramall, the late Lord Brittan and former Tory MP Harvey Proctor.

Mr Proctor blasted the force, calling the episode "a truly disgraceful chapter in the history of British policing".

Northumbria Police was later tasked with investigating his claims and the vicar's son, from Gloucester, was charged with 12 counts of perverting the course of justice and one of fraud, which he denied.

The prosecution alleged that Beech deliberately and persistently lied to police and fraudulently claimed £22,000 in criminal injuries compensation.

The prosecution described him as a "manipulative paedophile" after telling the jury he has previously admitted downloading indecent images of boys, and voyeurism.

Beech told detectives over hours of tearful interviews how his late step-father, an Army Major, raped him, then passed him on to generals to be tortured at military bases and sadistically sexually abused by other Establishment figures in the 1970s and 1980s.

He named former prime minister Sir Edward Heath, his sworn enemy Mr Proctor, disgraced TV star Jimmy Savile and security chiefs Sir Michael Hanley, the head of MI5, and MI6 boss Sir Maurice Oldfield among the gang after meeting a journalist from the defunct news agency Exaro.

He claimed a schoolboy named Scott was deliberately knocked down and killed, that another boy who might have been the missing teenager Martin Allen was raped and strangled in front of him and said another youth was battered to death by the ring.

A senior detective wrongly called the allegations "credible and true" before the force had completed their inquiries.

The defence claimed that the events he described did happen, or that Beech genuinely believed that they did.

But a jury at Newcastle Crown Court rejected Beech's unfounded allegations and on Monday convicted him of 12 counts of perverting the course of justice and one of fraud, relating to a £22,000 criminal injuries payout he falsely claimed for being raped by Savile.

In a statement released after Beech's conviction, Mr Proctor said the reputations of himself and other high-profile figures had been besmirched as a result of the false allegations, describing Met Police's Operation Midland probe that resulted from them as "rogue, malicious and apparently homophobic".

Mr Proctor listed a catalogue of supposed failings on the Metropolitan Police's part, and criticised Labour's deputy leader Tom Watson because he "gave oxygen" to Beech's claims by meeting with him and discussing the allegations.

He said: "The Metropolitan Police were lapdogs to Mr Watson's crude dog whistle. It's time for the torchlight to take a closer look at Mr Watson.

"It is now beyond doubt that all of these allegations could never have been true and only someone with spectacular bad judgement could think that they might be.

"It is time for an apology from him to me and everyone named or implicated in this truly disgraceful chapter in the history of British policing, which was allowed to happen because of internal failings at the highest level within the Metropolitan Police Service."

During the trial, jurors were shown a videoed police interview with Lord Bramall where the war hero, now too ill to give evidence, thumped the table in front of him and denied having any sexual interest in children.

Another falsely accused general, 96-year-old Sir Hugh Beach, told the jury via video-link that the allegations against him were "beyond grotesque".

Beech had also said the head of MI5 arrived at his school to tell him his dog had been kidnapped as a warning.

He claimed that he was there when the ring shot his horse Sam, although he had no idea what happened to the body, or what his mother thought, who was paying for its stabling.

With what Tony Badenoch QC, prosecuting, described as "breathtaking hypocrisy", Beech himself was a paedophile with an interest in pre-teen boys.

The school governor was due to be tried on indecent images and voyeurism charges last summer but went on the run to Sweden, where he bought two remote properties and tried to evade justice using false identities.

Mr Justice Goss said he will sentence on these matters, as well as indecent images offences and breach of bail, at a later date.

Speaking after the conviction, Birmingham University Emeritus Professor David Wilson said he believed Beech exploited the "moral panic" that followed the Savile scandal.

Beech, he said, used the "perfect storm" of the police and media's determination not to be caught out again following the disgraced TV star's death, and the timing of his allegations ensured his far-fetched story was given greater credence than it deserved.

The jury deliberated for around four-and-a-half hours.

Beech did not visibly react when the 13 guilty verdicts were returned.