Image copyright PA

Teachers, civil servants and police staff are among 264 people who have been charged in a probe targeting child abuse images online.

A total of 745 suspected paedophiles have been arrested in the National Crime Agency's Operation Notarise, launched just over a year ago.

The agency said 518 children had been protected as a result.

Of those charged, 47 were employed in positions of trust or voluntary roles with access to children, the NCA said.

Those facing charges include:

16 teachers, school or college staff

Six government workers, including three civil servants

One retired magistrate

One person working in the office of a police and crime commissioner

One person retired from "police service" work

One former UK Border Agency officer

The charges range from taking indecent images of children to committing sexual offences.

In addition 16 other people have been cautioned by police.

'Difficult lessons'

Operation Notarise is the largest UK inquiry into people sharing child abuse images online since Operation Ore in 2002.

NCA director general Keith Bristow said the organisation's response to the problem was "improving significantly", but warned "further difficult lessons" may lay ahead.

He said the volume of work related to online paedophile cases had placed a strain on investigators and said the criminal justice system may need to adapt to cope with the scale of offending.

Mr Bristow expressed concerns about the ability to identify suspects quickly enough by "resolving" their internet protocol (IP) addresses, and establishing evidence to bring perpetrators to justice.

He added: "We are going to need to think differently about what the criminal justice process might look like for some of these people.

"We absolutely don't subscribe to the view that people who have accessed images should be offered an outcome that falls short of criminal justice outcomes.

"But our judgment is that criminal justice intervention will potentially need to offer some sort of support to prevent people from reoffending."

He said investigations increasingly took into account the risk posed by individuals who access images of abuse.