Live-streaming websites are "enabling" paedophiles to widely share videos of child sexual abuse by failing to effectively combat the threat, an inquiry has heard.
Keith Niven, deputy-director support at the Child Exploitation and Online Protection Command (Ceop), said internet companies had a "long way to go" in quashing paedophilia on their sites.
About 80,000 potential cases of online child abuse were referred to Ceop, Britain's lead child protection squad, during 2017, it was revealed.
The Independent Inquiry into Child Sexual Abuse (IICSA) is currently holding hearings examining the role of the internet in paedophilia cases.
Predators have increasingly turned to live-streaming sites to broadcast footage of children being sexually exploited for an audience.
Mr Niven described it as an "emerging threat" of which it was "very difficult" to establish the scale.
He added: "The issue that we have here is that the products and services on the internet are enabling this form of abuse to take place.
"My view is that it is now time for industry to take a look at how these products and services have enabled this to take place and put in prevention measures to stop that happening, not only on the sites and services that are currently being used, but in the design of any new products and services as well.
"Because we have to prevent this - we have to prevent it at source, because it is an enabler and it is being used and it is being abused.
"So the National Crime Agency, we do work with industry, it is a very positive relationship that we have and industry have worked and improved, in my view, but there is a long way to go."
The senior officer said the number of referrals being received by Ceop about potential paedophiles operating online had been rising in recent years, with tip-offs chiefly coming from the public, websites and US monitoring agencies.
It has steadily climbed since April 2015, the hearing was told, reaching 3,500 referrals a month by the three months ending August 2016.
Sometimes referrals are the same viral image being disseminated by disgusted online users hoping to warn others, rather than offenders, Mr Niven said.
However, he denied the relatively low number of arrests made by the National Crime Agency (NCA), of which Ceop is a part, was inadequate given its resources and budget.
A total of 170 child abuse arrests were made across the NCA in 2016-17, counsel to the inquiry Jacqueline Carey said, while there were no nationally co-ordinated operations in 2016 to 2017.
Mr Niven said: "We are operating at the high end of high harm - these are complex investigation, involving incredibly dangerous individuals.
"It is not about volume, it is about threat risk and harm. It is right and proper that we target those individuals who do pose the highest harm to children."
He added that individual forces were now trained to tackle the issue of offenders targeting child victims over the internet, minimising Ceop's involvement.
"It is not a case of washing our hands of the case," he told the hearing.
"It is that we are confident that when we have disseminated those forces, they are disseminated to professional officers who are trained in child protection that have dedicated units to deal with this."
Referrals about depraved material is prioritised by police using a system know as the Kent Internet Risk Assessment Tool (Kirat), with an overall correct prediction rate of 83.7%, it was heard.
Challenged on the remaining cases that slipped through the net, Mr Niven said: "It is a tool, it has got a significantly high success rate, but it is not the only part of investigation."