Paedophile geophysicist Matthew Falder admits more than 130 charges

A gifted young scientist has admitted cajoling children and adults into online sex abuse and blackmailing them into performing even more degrading acts.

Geophysicist Dr Matthew Falder, 28, led a secret double life during years of study at Cambridge University, where he was known as a fun party-goer.

He used many false identities to befriend more than 50 victims on internet marketplace sites such as Gumtree.

Falder - who pleaded guilty to 137 charges at Birmingham Crown Court on Monday - persuaded them to send him naked or partially clothed pictures of themselves, then threatened them with exposure unless they went much further.

He shared many of the images in sex abuse forums on the hidden dark web where he used identities including '666devil' and 'evil mind'.

Falder targeted his victims for more than eight years before he was unmasked by the National Crime Agency. During the investigation the NCA sought help from GCHQ, the Government's communications spy centre, and other agencies.

His victims were girls, boys, women and men. Some were so traumatised they self-harmed, or attempted suicide.

His father Stephen Falder said: "This has turned our lives upside down. It came as a complete shock and the family is totally devastated."

Falder's long-term girlfriend, a fellow Cambridge student with whom he had shared a home, was said to be struggling to cope with the revelations since his arrest in June.

Falder, who grew up in a wealthy part of Cheshire, admitted charges including inciting the sexual exploitation of a child, causing a child to engage in sexual activity, voyeurism, making and distributing indecent images of children, fraud, blackmail and encouraging rape.

Dozens more charges were ordered to be left on his file.

Mike Hames, former head of Scotland Yard's Paedophile Squad, said: "He is a very nasty and savage individual. Although his crimes were non-contact, they are very similar to hands-on abuse, by inducing his victims, by whatever means, into doing things they wouldn't normally do.

"And thereafter he would exercise his power over them to make them feel awful about themselves in many ways. It was a bit similar to rape."

Falder was arrested at Birmingham University where he worked as a post-doctoral researcher.

During a long investigation by the National Crime Agency, investigators found that Falder had installed secret cameras to spy on more victims in compromising situations.

Clever as he was, he had inadvertently filmed himself while setting up the hidden cameras.

Matt Sutton, NCA senior investigating officer, said: "In 30 years of law enforcement I have never come across such horrifying offending where the offender's sole aim was to cause such pain and distress.

"It has been an extremely complex investigation into a prolific online predator, who over several years believed he could evade law enforcement to sexually and sadistically exploit vulnerable victims.

"I urge anyone who is being abused online to talk to somebody, report it. There is help available."

A GCHQ spokesperson said: "GCHQ is proud to have supported The National Crime Agency in this investigation.

"Working to counter this kind of terrible child sexual exploitation is an important part of our mission to help keep the UK safe online and protect the digital homeland."

A University of Cambridge spokesperson confirmed Falder was a student between 2007 and 2016 and said it was "deeply shocked and saddened" by the case.

Falder will be sentenced on 7 December and is expected to be given a long jail term.