He had denied several offences, including filming himself sexually assaulting a girl, but jurors found him guilty after just 11 minutes deliberation.

The victim in that case said Dodds made her feel as if she did not belong in the world.

Dodds’ offences included blackmail and multiple counts of causing the sexual exploitation of a child and inciting a child to engage in sexual activity.

Recorder Thomas Moran said Dodds had shown “breathtaking arrogance” and his actions were “cunning” and “outrageous”.

The “highly dangerous” Dodds presented himself as a “self-obsessed and self-pitying individual”, the judge said.

Recorder Moran said among the “striking and shocking” offences was one girl who Dodds abused after she confided in him about the recent death of her parent, including on Christmas Eve which should have been “an exciting and special day for any child”.

The judge said chat logs between Dodds and his victims made for “truly disgusting reading” and there was the “sadistic element” of the paedophile wanting to see the children in pain as they performed sexual acts.

He said the psychological harm caused to the victims was significant and might not become apparent until later in their lives.

In addition to his jail term Dodds must serve a further six years on extended licence, was made subject of a sexual harm prevention order to last indefinitely and must sign the sex offenders register until further notice.