More than 3,000 offences of grooming children online for sex have been committed by paedophiles in only the first year since a new law on sexual communication was introduced last April, police have revealed.

Facebook, Snapchat and Instagram accounted for almost three-quarters of the cases with sexual predators targeting children through a total of 80 different sites, apps or platforms, according to the figures obtained from police forces by the NSPCC. They youngest victim was just five years old.

The 3,171 offences are more than 50 per cent higher than the NSPCC expected in the first year based on what happened after similar legislation on sexual communication with a child was introduced in Scotland. A fifth of the cases involved children under 10.

The data has been revealed as part of The Telegraph’s Duty of Care campaign, which calls on the government to make social media and online gaming companies subject to a statutory duty to protect children from harms such as grooming, addiction and bullying.

Peter Wanless, NSPCC chief executive, told The Telegraph, in advance of the NSPCC’s annual report and conference on child safety online:: “These numbers are far higher than we had predicted, and every single sexual message from an adult to a child can have a huge impact for years to come.