A science teacher now living in Spalding has pleaded guilty to possessing more than 8,600 nude or erotic images of children.
Martyn Baxter-Smith (45) appeared at Boston Magistrates' Court today (Wednesday) and admitted four charges of possessing indecent images of children between August 7, 2007, and April 23 of this year.
After police searched the Boston Grammar School teacher's computer they found 8,644 level one images of children depicting nudity or erotic posing and 35 level two images depicting non-penetrative activity between two children.
They also found videos depicting nudity or non-penetrative sexual activity between children.
Child pornography is graded from levels one to five, level one the lowest and five the highest.
Prosecutor Marie Stace said the images of girls were aged between four and 14 and that there was "no suggestion" that Baxter-Smith, formerly of Wyberton, was distributing the images to others.
In defence, Hilary McLoughlin said Baxter-Smith's collection was "only for personal use".
He will be sentenced at Lincoln Crown Court at a later date after magistrates declined to pass sentence.
Baxter-Smith was released on bail on the condition he resides at his address in Clarence Gardens and that he is not allowed to be in the company of under 16s unsupervised.