A teacher from Gresford, near Wrexham has been told he faces a jail term after being convicted of using his computer to access child pornography.
Mulvey taught biology and was head of year eight at a school in Crewe
David Mulvey, 51, who taught in Crewe, Cheshire, denied all knowledge of how 243 images and eight video clips had got onto his home computer.
The police, tipped off by their Italian counterparts, went to his home as he downloaded two images, the court heard.
The judge at Mold Crown Court adjourned sentence for a week and bailed Mulvey.
Mulvey, who entered teaching at the age of 47, was unanimously convicted of possessing the images and making one level four image of a child by downloading it off the internet.
The jury then retired again and convicted him of a further 11 counts of making indecent images by downloading them, by a majority of 10 to two.
Rhys Rowlands, prosecuting, told the court that Mulvey had used a programme aimed at removing evidence of internet activity to try and hide his activities.
But North Wales police had been able to recover a large number of images from the computer's hard drive using sophisticated software, he said.
When police officers later visited his school and examined his laptop computer, they discovered that someone had used a search word "Lolita" on it, the jury heard.
Mulvey, who was suspended from his teaching position at St Thomas More Catholic High School when the allegations were first made, told the court he had been using software to clean up files on his computer because of problems with his machine.
When asked about the search on the word "Lolita", Mulvey told the court that he had allowed a pupil - who he later found out was banned from using computers at school - to use his laptop.
But he denied he had been interrupted when downloading two images from an Italian child pornography site when police officers came to his door in December.
Mulvey, who in addition to teaching biology was head of year eight at the school, said he had worked very hard to get to where he was.
"I am not going to destroy all of that by doing that sort of thing," he told the court.
Judge John Rogers QC told Mulvey, who is married, that he faced an inevitable prison sentence.
But he agreed to adjourn sentencing for a week after Mulvey's defending barrister said it would give him time to make the necessary arrangements.