Married father-of-three Stuart Robert Rees admitted to possessing thousands of indecent images of children, some as young as two.
According to Wales Online, police went to the former geography teacher's home and investigated his computer equipment.
“It is of a particularly indecent, unpleasant and graphic nature"
On searching 51-year-old's computer, police found almost 3,500 graphic images at categories A, B and C (A being the most severe) of children - one of whom was a girl under the age of four.
There was also a graphic movie in a shared folder, which featured a young girl, aged somewhere between the ages of seven and nine, being raped.
Sarah Waters, the lawyer for the prosecution, also revealed that Rees had set up fake accounts on social media websites, posing as a young girl with access to very young children.
This suggested that sexual activity had been carried out with babies.
“It is of a particularly indecent, unpleasant and graphic nature,” said Ms Waters.
Rees, who ended his career as a teacher when he entered a guilty plea at the magistrate's court, went on to work as a delivery driver for Asda, and was involved in a charitable organisation.
Ruth Smith, the lawyer acting in his defence, said that he is still being supported by his wife - who has also lost her job as the result of the trial - but added that his daughters have cut him out of their lives.
She said: “[Rees’s wife] has also lost her employment as a result of his actions. She was also involved in the teaching profession.
“They have become pariahs because of this.”
Rees has been jailed for 16 months, and will have to sign as a sex offender for 10 years.