The man accused of making up historical child sex abuse claims against high profile figures in Westminster, is himself “a committed and manipulative paedophile”, a court has heard.

Carl Beech, known by the pseudonym Nick, is on trial at Newcastle Crown Court, accused of lying about “three child murders, multiple rapes, kidnapping, false imprisonment and widespread sexual abuse”.

His claims led to a £2m Metropolitan Police investigation, which ended with no further action being taken.

He denies 12 counts of perverting the course of justice and one count of fraud at Newcastle Crown Court.

Prosecutor Tony Badenoch QC told jurors Beech himself secretly hid indecent images of young boys, as well as a covert recording of a child using a toilet, on his iPad.

Beech was viewing “indecent images of the gravest kind and spying on small boys” at the same time as he was perpetuating “lies about Harvey Proctor and so many others”, Badenoch told the jury.

He said of Beech: “He committed the criminal offences of making and possessing indecent images of children and of voyeurism.”

The court was told that Beech was prosecuted in a separate trial in relation to those offences and, after initially pleading not guilty, had reversed his pleas to guilty after a jury had been sworn in.

Badenoch said that process had taken around “18 months” to complete, adding: “This evidence demonstrates that Carl Beech is a committed and manipulative paedophile, capable of deceit to investigators and limitless manipulation when required.”

He said that Beech was “the sort of individual concerned only for himself, unconcerned with the impact of others”, and he told the jury the 51-year-old had attempted to blame someone else for the indecent images and the covert filming.

The prosecutor said of the offending: “It also demonstrates that Carl Beech has an interest in child pornography.

“Not something which is learnt behaviour from something which happened, but the reverse.”

The 51-year-old, who was known for years by the pseudonym Nick, is accused of inventing claims that a group of high-profile figures in the military, security services and politics sexually and physically abused young boys.

His allegations, among them a claim that three young boys were murdered by members of the ring, prompted the £2 million Operation Midland investigation by the Metropolitan Police, jurors heard on Tuesday.

The operation led to the homes of Lord Brittan, Lord Bramall, who is a former head of the Army, and former MP Harvey Proctor being raided.

Badenoch told jurors on Tuesday that Beech’s accusations were “demonstrably untrue”, telling the court they were “totally unfounded, hopelessly compromised and irredeemably contradicted”.

Badenoch said: “It is quite impossible to conceive of allegations of a worse kind to be made.”

Beech went on the run to Sweden when his extremely damaging allegations were proved to be false, jurors were told.

He had drawn sketches that appeared to be related to the abuse he claimed to have suffered, including demons and smaller figures surrounded by red.

His claims were initially made to Wiltshire Police and then the Metropolitan Police, sparked the £2 million Operation Midland.

When that inquiry was ultimately stopped, Northumbria Police were tasked with looking into the accuser himself, and his three-bedroom rented property, with his £30,000 Ford Mustang convertible parked outside, was raided.

The trial continues.