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
A split set up this Sunday
Four Britons are dead after a serious crash in Al Khalas, a settlement roughly 30 miles north of the holy site of Mecca.
So-called Islamic State said they were behind the attack that targeted people receiving their national identification cards.