A Bradford schoolteacher who admitted being attracted to teenage boys downloaded nearly 3,000 indecent images of children from the internet, a Court heard today.

Police found a total of 2,970 images on 29-year-old Thomas Nassiri’s computer.

Leeds Crown Court was told that nine out of ten of the photographs were “level one”, the least serious of five levels. But 89 pictures were at level four.

The Recorder of Leeds, Judge Peter Collier QC, imposed a 12-week prison sentence. But he suspended it for two years to enable Nassiri to attend a Sex Offenders Treatment Programme, which probation said would considerably benefit him.

Nassiri, who had pleaded guilty to 21 charges of possessing pornographic images of children, will also be supervised for two years by the probation service, and was made subject of a Sexual Offences Prevention Order and ordered to register as a sex offender for five years.

After the case, Detective Constable John Higgins, of West Yorkshire Police’s Abusive Images Unit, said: “Thomas Nassiri was a man in a position of trust and someone who should have protected our children. Instead he chose to entrench himself in the world of online sexual exploitation of children.”

He said the unit would robustly investigate and prosecute offenders who put children at risk online, and urged parents to take an active interest in their children’s internet activity.

The court heard Nassiri had qualified as a teacher in 2004 and had worked at Bradford Grammar School and Challenge College in Bradford. At the time of his arrest, in November 2007, he was teaching at Queensbury High School. He was then suspended and later resigned.

Prosecutor Stephen Uttley said Nassiri was arrested at his home in Alfred Street, Churwell, Morley, after information from the German authorities about people downloading indecent images of children from the internet.

Mr Uttley said all the images in the case related to young children. He said Nassiri had been looking at the porn on his computer for six or seven years, including during his training and employment as a teacher.

Nassiri at first told police he was not interested in boys under 18. Later he admitted he could find a teenager attractive, but not between the ages of 12 and 15.

Robin Frieze, mitigating, said Nassiri had fallen into a pattern of accessing level one material.

“The remaining material came in a way that was reckless. It wasn’t what he was seeking out, or interested in,” said Mr Frieze. He said Nassiri had been punished by the loss of his career and family estrangement and was not likely to re-offend.

Judge Collier said that if there was a lesson to be learned, it was that viewing low-level child porn led to looking at more serious images, and that the activities were being monitored and were likely to come to light.

Nassiri covered himself in a hooded coat and refused to comment as he left court.