A JUDGE has commended the tireless and painstaking detective work of investigators who put a sex predator behind bars.

Christopher Grinter was locked up for five years on Tuesday for a string of sickening offences against vulnerable children across the UK.

His activities came to light when the parents of two of his teenage victims contacted the Child Exploitation and Online Protection (CEOP) centre.

The organisation, which has helped track down some of the world’s most evil paedophiles, passed on details to police in North Yorkshire.

Officers raided Grinter’s home in Forcett, near Richmond, in September 2007 and seized his computer equipment.

It was discovered that the 26-year-old had amassed a collection of indecent homemade photos and videos over more than three years.

Grinter was said to have acted like a film director, persuading teenagers to pose for him using webcams linking his home and those of the girls.

He groomed at least 26 victims from across the country – and even more abroad – during a campaign of control and coercion.

Teesside Crown Court was told he would take freezeframe photographs or videos and store them alongside text exchanges as keepsakes.

Detective Constable Gary Treweek, PC Lisa Ayres and computer expert Ian Meek were praised by Judge George Moorhouse for their “dedication to duty”.

Det Con Treweek said last night: “We are very satisfied with the outcome of the case, which was the culmination of an extremely complex and intensive investigation, with victims throughout the length and breadth of the country.

“The invaluable support and expertise provided by CEOP was crucial from the outset of this investigation.

We have no doubt that Grinter would have continued to prey on young, naive and vulnerable girls in internet chatrooms and websites if his despicable activities were not reported to CEOP in the first instance.”

He added: “It is important that young people learn from this case and heed the warnings to be extra careful when online. The key safety message is simple: Do not divulge personal information to complete strangers.

“If you feel threatened or you are being pressurised into doing things that you do not want to do, then do not hesitate to report it to the local police, a teacher, a parent or online to CEOP.

“Parents also need to keep a watchful eye on their children’s internet usage.

“It is extremely disturbing to think that the girls involved in the investigation were approached by this perverted man while sat in their own homes. It’s a chilling thought – but it is one everybody must wise-up to.”