Pedophiles can use highly skilled techniques to gain kids’ trust and groom them in under 20 minutes, a study claims.

In the study, some 192 web chats between pedophiles and experts posing as kids were studied over four years.

Predators were from 21 to 65 years old and time between contact and first sexual request ranged from 18 minutes to 82 hours.

The vast majority also admitted they were adults, dispelling the popular belief they always pretend to be children.

Dr. Cristina Izura from Swansea University in Wales said groomers were skilled communicators who use a range of strategies, including seemingly innocuous small talk to develop trust.

She added: “They also compliment children regularly on a range of topics, rather than only sexually oriented ones.”

This helped form emotional bonds as well as “desensitizing them to sexual behavior.”

Many interactions go undetected by anti-grooming software, the research found.

Experts urged parents to get their kids to open up about their digital lives.

Izura said: “Taking an interest in their online activities is a good way to build their trust in us and help reduce the risk of them looking for trust elsewhere online.”

A National Society for the Prevention of Cruelty to Children spokeswoman said: “We hope this will help educate young people about staying safe, and assist the police in catching offenders.”