NCA deputy director general Phil Gormley said the scale of offending discovered by the child abuse operation was "shocking".
His colleague, chief constable Simon Bailey, said the number of indecent images of children has risen from under 10,000 in the 1990s to a figure in the tens of millions today.
More top news
An inquest has heard Charlie Jermyn died just 30 hours after he was born because he was not given the right antibiotics.
A British traveller was kicked out of Thailand by border officers after using pages of her passport as toilet paper when she was drunk.
Liverpool's owners have performed a U-turn on proposed ticket increases following a mass walkout of fans at weekend's Premier League match.